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  • 1.
    Albertsson, Ann-Christine
    et al.
    KTH, Skolan för kemivetenskap (CHE).
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE).
    Finne Wistrand, Anna
    KTH, Skolan för kemivetenskap (CHE). Royal Inst Technol, Sch Chem Sci & Engn, SE-10044 Stockholm, Sweden..
    POLY 554-Controlled synthesis of star-shaped homo- and co-polymers of aliphatic polyesters2006Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 232Artikkel i tidsskrift (Annet vitenskapelig)
  • 2.
    Albertsson, Ann-Christine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Finne-Wistrand, Anna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Controlled synthesis of star-shaped homo- and co-polymers of aliphatic polyesters2006Inngår i: 7th International Biorelated Polymers Symposium, 2006, s. 37-38Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The challenges in finding a material with the proper characteristics for a given tissue engineering application are several. One solution is improving the ability to tailor the mechanical and physical properties along with the degradation profile of aliphatic polyesters, by for example alterations in their composition and architecture. In this study, well-defined star-shaped aliphatic polyesters constituted of four arms were synthesized. As a model system, L,L-lactide and a spirocyclic tin initiator was chosen and the affect of the solvent, temperature and monomer-to-initiator ratio on the number average molecular weight, the molecular weight distribution and the conversion of the polymers was shown. Consecutively, we proved that well-defined star-shaped block copolymers composed of 1,5-dioxepan-2-one and L,L-lactide with narrow molecular weight distributions and controlled block lengths can be synthesized using this system.

  • 3.
    Arias, Veluska
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Polylactides with "green" plasticizers: Influence of isomer composition2013Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 130, nr 4, s. 2962-2970Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Synthesized polylactides (PLA) with different D-isomer contents in the polymer chain were melt-blended with a series of green plasticizers by extrusion. Mechanical and thermal properties as well as the morphology of the plasticized materials were characterized to demonstrate how the combination of PLA with different D-contents and plasticizer controls the material properties. After addition of acetyl tributyl citrate (ATC), the elongation at break for PLA with a low D-isomer content was twice as high as that for PLAs with high D-isomer contents. Similar variations in the plasticization effect on the PLAs were also observed with the other plasticizers used, glyceryl triacetate (GTA), glycerol trihexanoate (GTH) and polyethylene glycol (PEG). In order to continue with the development of renewable polymers in packaging applications, the interrelation between a plasticizer and a specific polymer needs to be understood.

  • 4.
    Arias, Veluska
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Tailoring the hydrolytic endurance of Poly(L-lactide)-based products2014Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Artikkel i tidsskrift (Annet vitenskapelig)
  • 5.
    Arias, Veluska
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Tuning the Degradation Profiles of Poly(L-lactide)-Based Materials through Miscibility2014Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 15, nr 1, s. 391-402Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effective use of biodegradable polymers relies on the ability to control the onset of and time needed for degradation. Preferably, the material properties should be retained throughout the intended time frame, and the material should degrade in a rapid and controlled manner afterward. The degradation profiles of polyester materials were controlled through their miscibility. Systems composed of PLLA blended with poly[(R,S)-3-hydroxybutyrate] (a-PHB) and polypropylene adipate (PPA) with various molar masses were prepared through extrusion. Three different systems were used: miscible (PLLA/a-PHB5 and PLLA/a-PHB20), partially miscible (PLLA/PPA5/comp and PLLA/PPA20/comp), and immiscible (PLLA/PPA5 and PLLA/PPA20) blends. These blends and their respective homopolymers were hydrolytically degraded in water at 37 degrees C for up to I year. The blends exhibited entirely different degradation profiles but showed no diversity between the total degradation times of the materials. PLLA presented a two-stage degradation profile with a rapid decrease in molar mass during the early stages of degradation, similar to the profile of PLLA/a-PHB5. PLLA/a-PHB20 presented a single, constant linear degradation profile. PLLA/PPA5 and PLLA/PPA20 showed completely opposing degradation profiles relative to PLLA, exhibiting a slow initial phase and a rapid decrease after a prolonged degradation time. PLLA/PPA5/comp and PLLA/PPA20/comp had degradation profiles between those of the miscible and the immiscible blends. The molar masses of the materials were approximately the same after 1 year of degradation despite their different profiles. The blend composition and topographical images captured at the last degradation time point demonstrate that the blending component was not leached out during the period of study. The hydrolytic stability of degradable polyester materials can be tailored to obtain different and predetermined degradation profiles for future applications.

  • 6.
    Arias, Veluska
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Nano-Stereocomplexation of Polylactide (PLA) Spheres by Spray Droplet Atomization2014Inngår i: Macromolecular rapid communications, ISSN 1022-1336, E-ISSN 1521-3927, Vol. 35, nr 22, s. 1949-1953Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A direct, efficient, and scalable method to prepare stereocomplexed polylactide (PLA)-based nanoparticles (NPs) is achieved. By an appropriate combination of fabrication parameters, NPs with controlled shape and crystalline morphology are obtained and even pure PLA stereocomplexes (PLASC) are successfully prepared using the spray-drying technology. The formed particles of varying D- and L-LA content have an average size of approximate to 400 nm, where the smallest size is obtained for PLA50, which has an equimolar composition of PLLA and PDLA in solution. Raman spectra of the particles show the typical shifts for PLASC in PLA50, and thermal analysis indicates the presence of pure stereocomplexation, with only one melting peak at 226 degrees C. Topographic images of the particles exhibit a single phase with different surface roughness in correlation with the thermal analysis. A high yield of spherically shaped particles is obtained. The results clearly provide a proficient method for achieving PLASC NPs that are expected to function as renewable materials in PLA-based nanocomposites and potentially as more stable drug delivery carriers.

  • 7.
    Arias, Veluska
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Fiberteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Fiberteknologi.
    Homocomposites of Polylactide (PLA) with Induced Interfacial Stereocomplex Crystallites2015Inngår i: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 3, nr 9, s. 2220-2231Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The demand for “green” degradable composite materials increases with growing environmental awareness. The key challenge is achieving the preferred physical properties and maintaining their eco-attributes in terms of the degradability of the matrix and the filler. Herein, we have designed a series of “green” homocomposites materials based purely on polylactide (PLA) polymers with different structures. Film-extruded homocomposites were prepared by melt-blending PLA matrixes (which had different degrees of crystallinity) with PLLA and PLA stereocomplex (SC) particles. The PLLA and SC particles were spherical and with 300–500 nm size. Interfacial crystalline structures in the form of stereocomplexes were obtained for certain particulate-homocomposite formulations. These SC crystallites were found at the particle/matrix interface when adding PLLA particles to a PLA matrix with d-lactide units, as confirmed by XRD and DSC data analyses. For all homocomposites, the PLLA and SC particles acted as nucleating agents and enhanced the crystallization of the PLA matrixes. The SC particles were more rigid and had a higher Young’s modulus compared with the PLLA particles. The mechanical properties of the homocomposites varied with particle size, rigidity, and the interfacial adhesion between the particles and the matrix. An improved tensile strength in the homocomposites was achieved from the interfacial stereocomplex formation. Hereafter, homocomposites with tunable crystalline arrangements and subsequently physical properties, are promising alternatives in strive for eco-composites and by this, creating materials that are completely degradable and sustainable.

  • 8.
    Arias, Veluska
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Odent, Jeremy
    Raquez, Jean-Marie
    Dubois, Philippe
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Toward "Green" Hybrid Materials: Core-Shell Particles with Enhanced Impact Energy Absorbing Ability2016Inngår i: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 4, nr 7, s. 3757-3765Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Restrained properties of "green" degradable products drive the creation of materials with innovative structures and retained eco-attributes. Herein, we introduce the creation of impact modifiers in the form of core-shell (CS) particles toward the creation of "green" composite materials. Particles with CS structure constituted of PLA stereocomplex (PLASC) and a rubbery phase of poly(epsilon-caprolactone-co-D,L-lactide) (P[CL-co-LA]) were successfully achieved by spray droplet atomization. A synergistic association of the soft P[CL-co-LA] and hard PLASC domains in the core-shell structure induced unique thermo-mechanical effects on the PLA-based composites. The core-shell particles enhanced the crystallization of PLA matrices by acting as nucleating agents. The core-shell particles functioned efficiently as impact modifiers with minimal effect on the composites stiffness and strength. These findings provide a new platform for scalable design of polymeric-based structures to be used in the creation of advanced degradable materials.

  • 9.
    Arias, Veluska
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Olsén, Peter
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Forecasting linear aliphatic copolyester degradation through modular block design2016Inngår i: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 130, s. 58-67Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of efficient methods to predict the degradation of renewable polymeric materials is continuously sought in the field of polymer science. Herein, we present a modular build-up approach to create polyester-based materials with forecasted degradation rates based on the hydrolysis of the constituent polymer blocks. This involved the strategic combination of critical factors affecting polyester hydrolysis, i.e. hydrophobicity and degree of crystallinity. The starting point of this method was a toolbox of polymers with different hydrophobicities and degrees of crystallinity, as well as an understanding of their inherent differences in hydrolysis rate. Knowledge of the hydrolysis of each polymer block module enabled the prediction of the overall degradation behavior of the constructed copolymers. Taking advantage of the primary factors that affect polymer degradation, block copolymers could be independently designed to incorporate soft or rigid and faster or slower degradation properties. This approach generated a shift for how molecular design can be used to predict the degradation behavior of intended materials for different applications.

  • 10.
    Arias, Veluska
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Olsén, Peter
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Selective degradation in aliphatic block copolyesters by controlling the heterogeneity of the amorphous phase2015Inngår i: Polymer Chemistry, ISSN 1759-9954, E-ISSN 1759-9962, Vol. 6, nr 17, s. 3271-3282Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Controlling the course of the degradation of aliphatic polyesters is a key question when designing new degradable materials. It is shown herein that it is possible to predetermine the degradation path of aliphatic block copolyesters by controlling the heterogeneity of the amorphous phase, which in turn regulates the availability of the hydrolyzable groups in the polyester backbone. To demonstrate these processes, we synthesized a set of degradable materials based on poly(l-lactide) (PLLA), poly(ε-decalactone) (PεDL) and poly(ε-caprolactone) (PCL) with varying compositions. The materials were subjected to hydrolysis for a six months period. The materials composed of PLLA and PεDL exhibited a heterogeneous amorphous phase, whereas the materials composed of PCL and PεDL presented a more homogeneous phase. The kinetics of the degradation indicated that the slowest degradation rate was observed for the more homogeneous compositions. The degradation path of the heterogeneous amorphous phase materials was driven by a random chain scission process, whereas the more homogeneous composition presented a degradation path driven by a more selective chain scission. The confinement of the amorphous phase by the more hydrolytically stable PεDL permitted a selective degradation of the available hydrolyzable groups. The random and more selective chain scission processes were further verified by using previously determined molecular modeling based on Monte Carlo procedures. Topographical images and thermal analyses of the materials under different degradation periods correlated with the proposed degradation paths. Detailed insights and the ability to predetermine the degradation pathways of aliphatic polyesters will continue to expand the great potential of renewable materials and their use in specific applications for a future sustainable society.

  • 11.
    Avalos, Arturo Salazar
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Superiorly Plasticized PVC/PBSA Blends through Crotonic and Acrylic Acid Functionalization of PVC2017Inngår i: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 9, nr 3, artikkel-id 84Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Superior plasticization efficiency was achieved by a grafting from functionalization of the PVC backbone. This was deduced to a synergistic effect of internal plasticization and improved intermolecular interactions between PVC and an oligomeric poly(butylene succinate-co-adipate) ( PBSA) plasticizer. A mild grafting process for functionalization of the PVC chain by crotonic acid ( CA) or acrylic acid ( AA) was used. The formation of PVC-g-CA and PVC-g-AA was confirmed by FTIR and H-1 NMR. Grafting with the seemingly similar monomers, CA and AA, resulted in different macromolecular structures. AA is easily homopolymerized and long hydrophilic poly( acrylic acid) grafts are formed resulting in branched materials. Crotonic acid does not easily homopolymerize; instead, single crotonic acid units are located along the PVC chain, leading to basically linear PVC chains with pendant crotonic acid groups. The elongation of PVC-g-CA and PVC-g-AA in comparison to pure PVC were greatly increased from 6% to 128% and 167%, respectively, by the grafting reactions. Blending 20% ( w/w) PBSA with PVC, PVC-AA or PVC-CA further increased the elongation at break to 150%, 240% and 320%, respectively, clearly showing a significant synergistic effect in the blends with functionalized PVC. This is a clearly promising milestone towards environmentally friendly flexible PVC materials.

  • 12.
    Backström, Eva
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Trash to Treasure: Microwave-Assisted Conversion of Polyethylene to Functional Chemicals2017Inngår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 56, nr 50, s. 14814-14821Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An effective microwave-assisted process for recycling low-density polyethylene (LDPE) waste into value-added chemicals was developed. To achieve fast and effective oxidative degradation aimed at production of dicarboxylic acids, nitric acid was utilized as an oxidizing agent. Different conditions were evaluated, where recycling time and concentration of oxidizing agent were varied and the end products were characterized by FTIR, NMR, and HPLC. After just 1 h of microwave irradiation at 180 degrees C in relatively dilute nitric acid solution (0.1 g/mL), LDPE powder was totally degraded. This transformation led to few well-defined water-soluble products, mainly succinic, glutaric, and adipic acids, as well as smaller amounts of longer dicarboxylic acids, acetic acid, and propionic acid. The length of the obtained dicarboxylic acids could to some extent be tuned by adjusting the reaction time, temperature, and amount of oxidizing agent. Finally, the developed process was verified by recycling LDPE freezer bags as model LDPE waste. The freezer bags were converted mainly into dicarboxylic acids with a yield of 71%, and the carbon efficiency of the process was 37%. The developed method can, thus, contribute to a circular economy and offers new possibilities to increase the value of plastic waste.

  • 13.
    Bäckström, Eva
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Designed from Recycled: Turning Polyethylene Waste to Covalently Attached Polylactide Plasticizers2019Inngår i: ACS SUSTAINABLE CHEMISTRY & ENGINEERING, ISSN 2168-0485, Vol. 7, nr 12, s. 11004-11013Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High-density polyethylene (HDPE) waste was successfully feedstock recycled, and the obtained chemicals were utilized for synthesis of plasticizers for polylactide (PLA). First, an effective route to recycle HDPE through a microwave-assisted hydrothermal process was established. This process led to selective degradation of HDPE to a few well-defined chemicals, namely, succinic, glutaric, and adipic acid. A model plasticizer was synthesized from the same composition of dicarboxylic acids, 1,4-butanediol, and crotonic acid. The function of crotonic acid was to produce oligomers with crotonate end groups for coupling the plasticizer to PLA main chain. The plasticizer was then blended with or coupled to PLA by a reactive extrusion process. Adding the plasticizer to PLA decreased the T-g and increased the strain at break, thus reducing the brittleness of the films. The addition of 20% (w/w) grafted plasticizer increased the strain at break of PLA from 6 to 156% and decreased the T-g by 15 degrees C compared with neat PLA. Finally, to verify the concept, a plasticizer was also synthesized from the dicarboxylic acid product mixture obtained from the feedstock recycling of HDPE. The recycled grafted plasticizer increased the strain at break of PLA to 142% and reduced the T-g by 10 degrees C. A promising route for designing from recycled feedstock, turning HDPE waste to PLA plasticizers, was thus demonstrated.

  • 14.
    Feng, Zhaoxuan
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Tunable chitosan hydrogels for adsorption: Property control by biobased modifiers2018Inngår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 196, s. 135-145Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A sustainable strategy to fabricate chitosan-based composite hydrogels with tunable properties and controllable adsorption capacity of trace pharmaceuticals was demonstrated. Two biobased modifiers were utilized to tune the properties, nano-graphene oxide (nGO) derived from chitosan via microwave-assisted carbonization and oxidation, and genipin as the crosslinking agent. An increase in genipin content facilitated an increase in the degree of crosslinking as shown by improved storage modulus and decreased swelling ratio. Increasing nGO content changed the surface microtopography of the hydrogel which correlated with the surface wettability. nGO also catalyzed the genipin-crosslinking reaction. The hydrogel was further shown to be an effective adsorbent for a common anti-inflammatory drug, diclofenac sodium (DCF), with the removal efficiency ranging from 91 to 100% after 48 h. DCF adsorption efficiency could be tuned through simple alteration of nGO and genipin concentration, which provides promising potential for this environmental-friendly adsorbent in removal of DCF from pharmaceutical waste water.

  • 15.
    Feng, Zhaoxuan
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Rajarao, Gunaratna Kuttuva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Industriell bioteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Microwave carbonized cellulose for trace pharmaceutical adsorption2018Inngår i: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 346, s. 557-566Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A promising sustainable strategy to valorize cellulose to high-value adsorbents for trace pharmaceuticals, like diclofenac sodium (DCF), in the water is demonstrated. Carbon nanospheres (CN) as the DCF adsorbent were derived from cellulose through a one-pot microwave-assisted hydrothermal carbonization method. CN exhibited efficient DCF removal (100% removal of 0.001 mg/mL DCF in 30 s and 59% removal of 0.01 mg/mL DCF in 1 h). The adsorption kinetics and isotherm data were well-fitted with the pseudo-second-order kinetic model and Langmuir model, respectively. The adsorption process was endothermic and spontaneous as confirmed by the thermodynamic parameters. Multiple characterization techniques including SEM/EDS, FTIR, FTIR-imaging and zeta potential were applied to qualitatively investigate the adsorption process. π-π stacking and hydrogen bonding were proposed as the dominant adsorption interactions. CN also demonstrated effective adsorption capacity towards three other commonly-detected contaminants in the wastewater including ketoprofen (KP), benzophenone (BZP), and diphenylamine (DPA), each bearing partial structural similarity with DCF. The affinity of the contaminants towards CN followed the order DPA > BZP > DCF > KP, which could be explained by the different configurations and chemical units. It was speculated that for DCF and KP, the steric hindrance and electrostatic repulsion produced by dissociated carboxyl groups can impede the adsorption process as compared to DPA and BZP. This methodology could offer further insights into the drug adsorption on the cellulose-derived carbon adsorbents and the use of bioderived carbons for treatment of wastewaters contaminated with pharmaceuticals.

  • 16.
    Feng, Zhaoxuan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Simeone, Antonio
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Biobased Nanographene Oxide Creates Stronger Chitosan Hydrogels with Improved Adsorption Capacity for Trace Pharmaceuticals2017Inngår i: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 5, nr 12, s. 11525-11535Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A promising green strategy for the fabrication of fully biobased chitosan adsorbents for wastewater purification is presented. Nanographene oxide (nGO)-type carbon dots were derived from chitosan (nGOCS) or from cellulose (nGOCL) through a two-step process including microwave-assisted hydrothermal carbonization and oxidation. Finally, nGO were evaluated as biobased property enhancers in chitosan hydrogel adsorbents. Macroporous chitosan hydrogels were synthesized by cross-linking with genipin, and the incorporation of nGO into these hydrogels was shown to facilitate the cross-linking reaction leading to more robust 3D cross-linked networks. This was evidenced by the increased storage modulus and by the swelling ratio that decreased from 5.7 for pristine chitosan hydrogel to 2.6 for hydrogel with 5 mg/mL nGOCS and 3.3 for hydrogel with 5 mg/mL nGOCL. As a further proof of the concept the hydrogels were shown to be effective adsorbent for the common anti-inflammatory drug diclofenac sodium (DCF). Here, the addition of nGO promoted the DCF adsorption process leading to 100% removal of DCF after only 5 h. The synergistic effect of electrostatic interactions, hydrogen bonding, and pi-pi stacking could explain the high adsorption of DCF on the hydrogels. The developed biobased CS/nGO hydrogels are thus promising adsorbents with great potential for purification of trace pharmaceuticals from wastewater.

  • 17.
    Feng, Zhaoxuan
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Takahiro, Danjo
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Tadahisa, Iwata
    Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo.
    Albertsson, Ann-Christine
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Recyclable fully biobased chitosan adsorbents spray-dried in one-pot to microscopic size and enhanced adsorption capacity2019Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, nr 5, s. 1956-1964Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A facile one-pot spray-drying process was developed for fabrication and in-situ crosslinking of chitosan microspheres to improve the adsorption capacity by microscopic design. A fully biobased nature was achieved by utilizing genipin (GP) as a crosslinking agent and chitosan derived nano-graphene oxide (nGO) as a property tuner. The produced chitosan microspheres were further proven as powerful adsorbents for common wastewater contaminants such as anionic dyes and pharmaceutical contaminants, here modelled by methyl orange (MO) and diclofenac sodium (DCF). By regulating the amount of GP and nGO, as well as by controlling the process parameters including the spraydrying inlet temperature and post-heat treatment, the surface morphology, size, zeta potential and adsorption efficiency of the microspheres could be tuned accordingly. The adsorption efficiency for MO and DCF reached 98.9 and 100 %, respectively. The microspheres retained high DCF adsorption efficiency after six adsorption and desorption cycles and the recyclability was improved by incorporated nGO. The fabricated microspheres, thus, have great potential as reusable and eco-friendly adsorbents.

  • 18.
    Glavas, Lidija
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Guo, Baolin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Finne Wistrand, Anna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Tuned electrical conductivity by macromolecular architecture: Electroactive and degradable block copolymers based on polyesters and aniline oligomers2012Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 244Artikkel i tidsskrift (Annet vitenskapelig)
  • 19.
    Glavas, Lidija
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Induced redox responsiveness and electroactivity for altering the properties of micelles without external stimuli2014Inngår i: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 10, nr 22, s. 4028-4036Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Control over micelle properties is vital in the field of drug delivery, and the ability to modify these properties in order to trigger dissociation is highly desirable. We prepared polymeric micelles with the ability to undergo dissociation over time without the need for external stimulation by incorporating an electroactive and redox responsive segment into amphiphilic copolymers. The incorporation of this segment also provides the ability to tailor the critical micelle concentration (CMC) and micelle size of the copolymers. Amphiphilic PEG-PLA copolymers were functionalized by coupling to an aniline pentamer in two different oxidation states (leucoemeraldine and emeraldine state). The incorporation of the electroactive and redox responsive aniline pentamer decreased the CMCs and the micelle size, independent of the oxidation state. However, the copolymers with the aniline pentamer in the leucoemeraldine state had significantly lower CMCs than the copolymers with the aniline pentamer in the emeraldine state. Simultaneously, stability tests performed on the functionalized micelles demonstrated the oxidation of the aniline segment, from the leucoemeraldine to the emeraldine state, over time. The oxidation led to an increase in the CMC, and the copolymers could thereby represent an excellent starting point for triggering drug release without external stimuli.

  • 20.
    Glavas, Lidija
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Redox responsiveness and electroactivity for preparation of smart micelles2014Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Artikkel i tidsskrift (Annet vitenskapelig)
  • 21.
    Glavas, Lidija
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Simultaneous Polymerization and Polypeptide Particle Production via Reactive Spray-Drying2016Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 17, nr 9, s. 2930-2936Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A method for producing polypeptide particles via in situ polymerization of N-carboxyanhydrides during spray-drying has been developed. This method was enabled by the development of a fast and robust synthetic pathway to polypeptides using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as an initiator for the ring-opening polymerization of N-carboxyanhydrides. The polymerizations finished within 5 s and proved to be very tolerant toward impurities such as amino acid salts and water. The formed particles were prepared by mixing the monomer, N-carboxyanhydride of L-glutamic acid benzyl ester (NCA(Glu)) and the initiator (DBU) during the atomization process in the spray-dryer and were spherical with a size of similar to 1 um. This method combines two steps; making it a straightforward process that facilitates the production of polypeptide particles. Hence, it furthers the use of spray-drying and polypeptide particles in the pharmaceutical industry.

  • 22.
    Glavas, Lidija
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Tuning loading and release by modification of micelle core crystallinity and preparation2015Inngår i: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581, Vol. 26, nr 7, s. 880-888Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Controlling and tuning the loading and release of incorporated drugs are vital parts of the advancement of drug delivery systems. Micelle systems that use core crystallinity to tune the loaded amount of hydrophobic molecules as well as their released amount were therefore developed. The conductive and electroactive aniline pentamer was incorporated into poly(ethylene glycol)-poly(epsilon-caprolactone) (PEG-PCL) micelles with semi-crystalline cores and poly(ethylene glycol)-poly(epsilon-decalactone) (PEG-P epsilon DL) micelles with amorphous cores. The difference in core crystallinity of the two micelle systems gave rise to highly different loading capacities and release rates. The loading capacity was strongly dependent on the core crystallinity, and the amorphous PEG-P epsilon DL micelles had almost twice as high loading capacity as the semi-crystalline PEG-PCL micelles. In addition, the loading capacity was highly influenced by the loading procedure. The dependence on core crystallinity was also evident for the release of the aniline pentamer. The release occurred faster for the PEG-P epsilon DL micelles with amorphous cores compared with the PEG-PCL micelles with semi-crystalline cores. The use of just these two systems gave us the ability to tune the released amount and rate, and a combination of these systems can enable access to a wide range of release profiles, thereby being available to a variety of drug delivery applications.

  • 23.
    Glavas, Lidija
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Olsén, Peter
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Achieving Micelle Control through Core Crystallinity2013Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 14, nr 11, s. 4150-4156Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have designed a pathway for controlling the critical micelle concentration and micelle size of polyester-based systems. This was achieved by creating an array of different copolymers with semicrystalline or amorphous hydrophobic blocks. The hydrophobic block was constructed through ring-opening polymerization of epsilon-caprolactone, L-lactide, and epsilon-decalactone, either as homopolymers or random copolymers, using PEG as both the initiator and the hydrophilic block. Micelles formed with amorphous cores exhibited considerably higher critical micelle concentrations than those with semicrystalline cores. Micelles with amorphous cores also became larger in size with an increased molecular weight of the hydrophobic bock, in contrast to micelles with semicrystalline cores, which displayed the opposite behavior. Hence, core crystallinity was found to be a potent tool for tailoring micelle properties and thereby facilitating the optimization of drug delivery systems. The introduction of PEG-P epsilon DL also proved to be a valuable asset in the tuning of micelle properties.

  • 24.
    Hakkarainen, Minna
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Tuning the release rate of acidic degradation products through macromolecular design of caprolactone-based copolymers2007Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 129, nr 19, s. 6308-6312Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Macromolecular engineering is presented as a tool to control the degradation rate and release rate of acidic degradation products from biomedical polyester ethers. Three different caprolactone/1,5-dioxepan-2-one (CL/DXO) copolymers were synthesized: DXO/CL/DXO triblock, CL/DXO multiblock, and random cross-linked CL/DXO copolymer. The relation of CL and DXO units in all three copolymers was 60/40 mol %. The polymer discs were immersed in phosphate buffer solution at pH 7.4 and 37 degrees C for up to 364 days. After different time periods degradation products were extracted from the buffer solution and analyzed. In addition mass loss, water absorption, molecular weight changes, and changes in thermal properties were determined. The results show that the release rate of acidic degradation products, a possible cause of acidic microclimates and inflammatory responses, is controllable through macromolecular design, i.e., different distribution of the weak linkages in the copolymers.

  • 25.
    Hedenqvist, Mikael S.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Merveille, A.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Bergman, G.
    Adhesion of microwave-plasma-treated fluoropolymers to thermoset vinylester2005Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 98, nr 2, s. 838-842Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Poly(tetrafluoroethylene) and a fluoroethylene copolymer were surface treated with a 2.45-GHz microwave plasma to enhance their adhesion to a vinylester thermoset. The plasmas were generated with an inert gas (Ar) and with reactive gases (H-2, O-2, and N-2). The lap-joint shear stress was measured on fluoropolymer samples glued with the vinylester. In general, the stress at failure increased with increasing plasma-energy dose. The H, plasma yielded the best adhesion, and X-ray photoelectron spectroscopy revealed that it yielded the highest degree of defluorination of the fluoropolymer surface. The defluorination efficiency declined in the order H-2, Ar, O-2, and N-2. Contact angle measurements and scanning electron microscopy revealed that the surface roughness of the fluoropolymer depended on the rate of achieving the target energy dose. High power led to a smoother surface, probably because of a greater increase in temperature and partial melting.

  • 26.
    Hua, Geng
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Franzén, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Phosphazene-Catalyzed Regioselective Ring-Opening Polymerization of rac-1-Methyl Trimethylene Carbonate: Colder and Less is Better2019Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 52, nr 7, s. 2681-2690Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The regioselective organocatalytic ring-opening polymerization (ROP) of a 6-membered cyclic carbonate, rac-1-methyl trimethylene carbonate, was studied using phosphazene base (t-BuP2) as the principle catalyst. The influence on the reaction kinetics caused by the reaction temperature (-74-60 degrees C), catalyst loading (0.5-2.5%), and reaction solvent (toluene and tetrahydrofuran) was systematically tuned and followed by H-1 NMR. All studied reactions reached close to or above 90% monomer conversion in 3 h, and all exhibited typical equilibrium polymerization behavior that is inherent to 6-membered cyclic carbonates. Good control over the molecular weight and distribution of the polycarbonate product was obtained in most studied conditions, with M-n ranging from similar to 4k to similar to 20k and D < 1.2. The regioregularity (X-reg) of the resulting polycarbonate was thoroughly studied using various NMR techniques, with the highest X-reg obtained being.0.90. The major influence from the reaction conditions on both the ROP kinetics and X-reg are as follows: higher reaction temperature resulted in a decrease of both; higher catalyst loading resulted in a faster ROP reaction but a slight decrease in X-reg; and toluene being a better solvent resulted in both faster reaction and higher X-reg. Throughout this study, we have demonstrated the possibility to synthesize regioregular aliphatic polycarbonate using an organic base as the ROP catalyst, contrary to the existing studies on similar systems where only metal-base catalysts were in focus and our systems showed similar high X-reg of the product.

  • 27.
    Hua, Geng
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Johan, Franzén
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    One-pot inimer promoted ROCP synthesis of branched copolyesters using α-hydroxy-γ-butyrolactone as the branching reagent2016Inngår i: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 54, nr 13, s. 1908-1918Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An array of branched poly(ɛ-caprolactone)s was successfully synthesized using an one-pot inimer promoted ring-opening multibranching copolymerization (ROCP) reaction. The biorenewable, commercially available yet unexploited comonomer and initiator 2-hydroxy-γ-butyrolactone was chosen as the inimer to extend the use of 5-membered lactones to branched structures and simultaneously avoiding the typical tedious work involved in the inimer preparation. Reactions were carried out both in bulk and in solution using stannous octoate (Sn(Oct)2) as the catalyst. Polymerizations with inimer equivalents varying from 0.01 to 0.2 were conducted which resulted in polymers with a degree of branching ranging from 0.049 to 0.124. Detailed ROCP kinetics of different inimer systems were compared to illustrate the branch formation mechanism. The resulting polymer structures were confirmed by 1H, 13C, and 1H-13C HSQC NMR and SEC (RI detector and triple detectors). The thermal properties of polymers with different degree of branching were investigated by DSC, confirming the branch formation. Through this work, we have extended the current use of the non-homopolymerizable γ-butyrolactone to the branched polymers and thoroughly examined its behaviors in ROCP.

  • 28.
    Hua, Geng
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Exploiting Ring-Opening Aminolysis–Condensation as a Polymerization Pathway to Structurally Diverse Biobased Polyamides2018Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A pathway to biobased polyamides (PAs) via ring-opening aminolysis–condensation (ROAC) under benign conditions with diverse structure was designed. Ethylene brassylate (EB), a plant oil-derived cyclic dilactone, was used in combination with an array of diamines of diverse chemical structure, and ring-opening of the cyclic dilactone EB was revealed as a driving force for the reaction. The ROAC reactions were adjusted, and reaction conditions of 100 °C under atmospheric pressure using 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as a catalyst for 24 h were optimal. The structures of the polyamides were confirmed by mass spectroscopy, FTIR, and NMR, and the PAs had viscosity average molecular weights (Mη) of ∼5–8 kDa. Glassy or semicrystalline PAs with glass transition temperatures between 48 and 55 °C, melting temperatures of 120–200 °C for the semicrystalline PAs, and thermal stabilities above 400 °C were obtained and were comparable to the existing PAs with similar structures. As a proof-of-concept of their usage, one of the PAs was shown to form fibers by electrospinning and films by melt pressing. Compared to conventional methods for PA synthesis, the ROAC route portrayed a reaction temperature at least 60–80 °C lower, could be readily carried out without a low-pressure environment, and eliminated the use of solvents and toxic chemicals. Together with the plant oil-derived monomer (EB), the ROAC route provided a sustainable alternative to design biobased PAs.

  • 29.
    Hua, Geng
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    From Food Additive to High-Performance Heavy Metal Adsorbent: A Versatile and Well-Tuned Design2016Inngår i: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A biosourced, cross-linked hydrogel-type heavy metal adsorbent is presented. Various factors such as the highly efficient chemical interactions, the various network structures, the decreased energy consumption during cross-linking, and the negligible amount of generated waste are considered when designing the adsorbent. The widely applied, naturally occurring food additive δ-gluconolactone is studied as a building block for the adsorbent. Aminolysis reactions were applied to form linear dimer precursors between diamines and δ-gluconolactones. The abundant hydroxyl groups on the dimers from δ-gluconolactone were fully exploited by using them as the cross-linking sites for reactions with ethylenediaminetetraacetic dianhydride, a well-known metal-chelating moiety. The versatility of the adsorbent and its metal-ion binding capacity is well tuned using dimers with different structures and by controlling the feed ratios of the precursors. Buffers with different pH values were used as the conditioning media to examine the swelling properties and the mechanical properties of the hydrogels, revealing that both properties can be controlled. High heavy metal chelating performance of the adsorbent was determined by isothermal adsorption kinetics, titration, and thermal gravimetric analysis. The adsorbent exhibits an outstanding chelating ability toward the three tested heavy metals (Cu(II), Co(II), Ni(II)), and the maximum adsorption capacity (qm ∼ 121 mg·g–1) is higher than that of the majority of the reported biosourced adsorbents.

  • 30.
    Hua, Geng
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Isocyanate-Free, UV-Crosslinked Poly(Hydroxyurethane) Networks: A Sustainable Approach toward Highly Functional Antibacterial Gels2017Inngår i: Macromolecular Bioscience, ISSN 1616-5187, E-ISSN 1616-5195Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An increased sustainabile awarness has inspired the development of new polymeric networks in a remarkable way and this strive should be combined with environmentally concerned end-uses. Therefore, a UV-crosslinked polyhydroxyurethane film with antibacterial properties is developed. First, a hydroxyurethane precursor is synthesized using aminolysis condensation, circumventing the use of isocyanates. The films are subsequently crosslinked under solvent-free conditions through a UV-triggered thiol-ene mechanism. The reactions are monitored by 1H nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy, and the networks have gel contents above 90%, and are transparent, hydrophilic, and highly flexible. Antibacterial properties are achieved by a controlled quaternization of the network's tertiary-amine and methylation of thiol-ether functionality, resulting in quaternary ammonium compounds (QACs) and sulfonium compounds. The antibacterial properties are evaluated against both Escherichia coli and Staphylococcus aureus using the agar plate diffusion and tube shaking methods. The QAC-loaded films exhibit outstanding bactericide properties (>99.9%) and the antibacterial mechanism is demonstrated to be a dual killing mechanism, i.e., diffusion killing and contact active killing.

  • 31.
    Hua, Geng
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Olsen, Peter
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Franzen, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Anionic polycondensation and equilibrium driven monomer formation of cyclic aliphatic carbonates2018Inngår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 8, nr 68, s. 39022-39028Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The current work explores the sodium hydride mediated polycondensation of aliphatic diols with diethyl carbonate to produce both aliphatic polycarbonates and cyclic carbonate monomers. The lengths of the diol dictate the outcome of the reaction; for ethylene glycol and seven other 1,3-diols with a wide array of substitution patterns, the corresponding 5-membered and 6-membered cyclic carbonates were synthesized in excellent yield (70-90%) on a 100 gram scale. Diols with longer alkyl chains, under the same conditions, yielded polycarbonates with an M-w ranging from 5000 to 16000. In all cases, the macromolecular architecture revealed that the formed polymer consisted purely of carbonate linkages, without decarboxylation as a side reaction. The synthetic design is completely solvent-free without any additional post purification steps and without the necessity of reactive ring-closing reagents. The results presented within provide a green and scalable approach to synthesize both cyclic carbonate monomers and polycarbonates with possible applications within the entire field of polymer technology.

  • 32.
    Höglund, Anders
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Crucial Differences in the Hydrolytic Degradation between Industrial Polylactide and Laboratory-Scale Poly(L-lactide)2012Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 4, nr 5, s. 2788-2793Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The rate of degradation of large-scale synthesized polylactide (PLA) of industrial origin was compared with that of laboratory-scale synthesized poly(L-lactide) (PLLA) of similar molar mass. The structural discrepancy between the two material types resulted in a significant difference in degradation rate. Although the hydrolysis of industrial PLA was substantially faster than that of PLLA, the PLA material became less brittle and fragmented to a lesser extent during degradation. In addition, a comprehensive picture of the degradation of industrial PLA was obtained by subjecting different PLA materials to hydrolytic degradation at various temperatures and pH's for up to 182 days. The surrounding environment had no effect on the degradation rate at physiological temperature, but the degradation was faster in water than in a phosphate buffer after prolonged degradation at temperatures above the T-g. The degree of crystallinity had a greater influence than the degradation environment on the rate of hydrolysis. For a future use of polylactide in applications where bulk plastics are generally used today, for example plastic packages, the appropriate PLA grade must be chosen based on the conditions prevailing in the degradation environment.

  • 33.
    Höglund, Anders
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Controllable Degradation Product Migration from Cross-Linked Biomedical Polyester-Ethers through Predetermined Alterations in Copolymer Composition2007Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 8, nr 6, s. 2025-2032Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Uniformly degrading biomaterials with adjustable degradation product migration rates were customized by combining the advantages of cross-linked poly(epsilon-caprolactone) with the hydrophilic character of poly(1,5-dioxepan-2-one). Hydrolytic degradation of these random cross-linked networks using 2,2'-bis-(epsilon-caprolactone-4-yl) propane (BCP) as the cross-linking agent was studied for up to 546 days in phosphate buffer solution at pH 7.4 and 37 degrees C. The hydrophilicity of the materials was altered by varying the copolymer compositions. After different hydrolysis times the materials were characterized, and the degradation products were extracted from the buffer solution and analyzed. Fourier transform infrared spectroscopy, differential scanning calorimetry, atomic force microscopy, scanning electron microscopy, and gas chromatography-mass spectrometry were used to observe the changes taking place during the hydrolysis. From the results it was concluded that degradation profiles and migration of degradation products are controllable by tailoring the hydrophilicity of cross-linked polyester-ether networks.

  • 34. Meszynska, Anna
    et al.
    Pollet, Eric
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Averous, Luc
    Effect of Oligo-Hydroxyalkanoates on Poly(3-Hydroxybutyrate-co-4-Hydroxybutyrate)-Based Systems2015Inngår i: Macromolecular materials and engineering (Print), ISSN 1438-7492, E-ISSN 1439-2054, Vol. 300, nr 6, s. 661-666Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study presents the utilization of oligo-hydroxyalkanoates obtained from controlled degradation of poly(3-hydroxybutyrate) as additives in a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer matrix (P(3HB-co-4HB)). These oligomers are compared to a conventional biobased plasticizer, used as reference, based on a monoglyceride acetate obtained from hydrogenated castor oil. Different multiphase systems are elaborated with these additives and characterized. Thermal and mechanical properties demonstrate that the monoglyceride acetate is as an efficient plasticizer increasing the elongation of the P(3HB-co-4HB) films while decreasing their maximum strength and elastic modulus. On the contrary, the addition of oligo-PHB results in an increased crystallinity of the matrix, thus improving the maximum strength and elastic modulus of the corresponding films. The oligomers act as an efficient reinforcing agent. Mobility brought by the oligomers induces a rearrangement of the P(3HB-co-4HB) with an increase of the chain rearrangement. Interestingly, the simultaneous addition of both additives results in significantly reduced T-g and improved elongation at break, as expected from an efficient plasticizer, but it also leads to P(3HB-co-4HB) films retaining relatively high strength and modulus values, thanks to the reinforcement ability of the oligo-PHB additive. Thermal characterization finally demonstrated that such mixed additives system results in greatly improved thermal stability of the polyhydroxyalkanoate copolymer matrix.

  • 35. Michalak, Michal
    et al.
    Kwiecien, Iwona
    Kwiecien, Michal
    Adamus, Grazyna
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Kurcok, Piotr
    Diversifying Polyhydroxyalkanoates - End-Group and Side-Chain Functionality2017Inngår i: Current Organic Synthesis, ISSN 1570-1794, E-ISSN 1875-6271, Vol. 14, nr 6, s. 757-767Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Background: Polyhydroxyalkanoates (PHAs) are a natural origin biodegradable polyesters consisted of various 3-and 4-hydroxyacid derived repeating units produced by microorganisms as energy storage. PHAs have been intensively studied due to their biodegradability and biocompatibility enabling their use both in packaging and agriculture as well as in medicine and pharmacy. PHAs obtained via biotechnological routes can possess various functional groups in their side chains. However, the diversity in their functionality is limited due to issues of conservation of functional groups during the polymer formation. Objective: The review focuses on recent progress in the area of synthesis of PHAs functionalized with various reactive as well as bioactive end and side groups. Conclusion: A potent route to resolve the problem of functional group diversity in natural origin PHAs involves post-polymerization modification, where the desired side groups can be created. On the contrary, synthetically produced PHA analogs obtained directly via ring-opening polymerization of beta-lactones offer various functionalities at different position throughout the polymer chain. The desired alpha-and omega-end groups can be introduced into the polymer chain using specific polymerization, initiation or termination strategies, respectively. The preferred side chain functionality is obtained by choosing the appropriate beta-lactone monomers bearing respective functional groups. All functional groups may also be subjected to additional chemical modification. The degradation of PHA as a method for producing functional polymers as well as their possible further applications are also discussed.

  • 36.
    Nugroho, Robertus Wahyu N.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Highlighting the Importance of Surface Grafting in Combination with a Layer-by-Layer Approach for Fabricating Advanced 3D Poly(L-lactide) Microsphere Scaffolds2016Inngår i: CHEMISTRY OF MATERIALS, ISSN 0897-4756, Vol. 28, nr 10, s. 3298-3307Artikkel i tidsskrift (Annet vitenskapelig)
  • 37.
    Nugroho, Robertus Wahyu N.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Nondestructive Covalent "Grafting-from" of Poly(lactide) Particles of Different Geometries2012Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 4, nr 6, s. 2978-2984Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A nondestructive "grafting-from" method has been developed using poly(lactide) (PLA) particles of different shapes as substrates and three hydrophilic monomers as grafts. Irregularly shaped particles and spheres of PLA were covalently surface functionalized using a versatile method of photoinduced free radical polymerization. The preservation of the molecular weight of the PLA particle bulk and the retention of the original particle shape confirmed the negligible effect of the grafting method. The changes in surface composition were determined by FTIR for both spherical and irregular particles and by XPS for the irregular particles showing the versatility of the method. Changes in the surface morphology of the PLA spherical particles were observed using microscopy techniques showing a full surface coverage of one of the grafted monomers. The method is applicable to a wide set of grafting monomers and provides a permanent alteration of the surface chemistry of the PLA particles creating hydrophilic PIA surfaces in addition to creating sites for further modification and drug delivery in the biomedical fields.

  • 38.
    Nugroho, Robertus Wahyu N.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    The nature of polymer grafts and substrate shape on the surface degradation of poly(l-lactide)2015Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Surface grafting of functional polymers is an effective method to alter material properties and degradation behavior. Two different substrate shapes of poly(l-lactide) (PLLA), i.e., films and microparticles, were surface-grafted with hydrophilic monomers, and their surface degradation was monitored. Surface grafting with a hydrophilic and acidic polymer graft [acrylic acid (AA)] induced large alterations in the surface morphology and topography of the films. In contrast, hydrophilic and neutral polymer grafts [acrylamide (AAm)] had no significant effect on the surface degradation behavior, while the PLLA reference and co-monomeric (AA/AAm) polymer-grafted samples exhibited intermediate surface degradation rates. The grafted PAA chains induced a local acidic environment on the surface of the substrates, which in turn catalyzed the surface degradation process. This effect was more pronounced in the films than in the microparticles. Thus, the nature of the grafted chains and substrate geometry were shown to affect the surface degradation behavior of PLLA substrates.

  • 39.
    Nugroho, Robertus Wahyu N.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Fiberteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Fiberteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Fiberteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Force interactions of grafted polylactide particles2014Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Artikkel i tidsskrift (Annet vitenskapelig)
  • 40.
    Nugroho, Robertus Wahyu N.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Roy, Prasun Kumar
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Crosslinked PVAL nanofibers with enhanced long-term stability prepared by single-step electrospinning2013Inngår i: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581, Vol. 24, nr 4, s. 421-429Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a single-step route for the preparation of crosslinked poly(vinyl alcohol) (PVAL) nanofibers where a conventional electrospinning setup can be used. The simple crosslinking chemistry and the fast and easily applicable technique is an important step towards large-scale production. In contrast to conventional systems, the PVAL crosslinker solution exhibited no increase in viscosity during storage and can therefore be used even after long shelf-times before electrospinning. In addition, the crosslinked nanofibrous mats exhibited a gel content of almost 100%, indicating complete crosslinking; they did not dissolve in water, and no PVAL was found in the aqueous extract. The E-moduli of the nanofibrous mats before and after water immersion could be measured by an intermodulation atomic force microscopy technique. A denser nanofibrous texture with enhanced mechanical properties can be observed after long-term water immersion.

  • 41.
    Nugroho, Robertus Wahyu Nayan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Fiberteknologi.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Force Interactions of Nonagglomerating Polylactide Particles Obtained through Covalent Surface Grafting with Hydrophilic Polymers2013Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 29, nr 26, s. 8873-8881Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

     Nonagglomerating polylactide (PLA) particles with various interaction forces were designed by covalent photografting. PLA particles were surface grafted with hydrophilic poly(acrylic acid) (PAA) or poly(acrylamide) (PAAm), and force interactions were determined using colloidal probe atomic force microscopy. Long-range repulsive interactions were detected in the hydrophilic/hydrophilic systems and in the hydrophobic/hydrophilic PLA/PLA-g-PAAm system. In contrast, attractive interactions were observed in the hydrophobic PLA/PLA and in the hydrophobic/hydrophilic PLA/PLA-g-PAA systems. AFM was also used in the tapping mode to determine the surface roughness of both neat and surface-grafted PLA film substrates. The imaging was performed in the dry state as well as in salt solutions of different concentrations. Differences in surface roughness were identified as conformational changes induced by the altered Debye screening length. To understand the origin of the repulsive force, the AFM force profiles were compared to the Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory and the Alexander de Gennes (AdG) model. The steric repulsion provided by the different grafted hydrophilic polymers is a useful tool to inhibit agglomeration of polymeric particles. This is a key aspect in many applications of polymer particles, for example in drug delivery.

  • 42.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Design of polyester and porous scaffolds2005Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The use of synthetic materials for tissue and organ reconstruction, i. e. tissue engineering, has become a promising alternative to current surgical therapies and may overcome the shortcomings of the methods in use today. The challenge is in the design and reproducible fabrication of biocompatible and bioresorbable polymers, with suitable surface chemistry, desirable mechanical properties, and the wanted degradation profile. These material properties can be achieved in various manners, including the synthesis of homo- and copolymers along with linear and star-shaped architectures. In many applications the materials’ three-dimensional structure is almost as important as its composition and porous scaffolds with high porosity and interconnected pores that facilitate the in-growth of cells and transportation of nutrients and metabolic waste is desired.

    In this work linear and star-shaped polymers have been synthesized by ring-opening polymerization using a stannous-based catalyst and a spirocyclic tin initiator. A series of linear copolymers with various combinations of 1,5-dioxepane-2-one (DXO), Llactide (LLA) and ε-caprolactone (CL) have been polymerized using stannous octoate as catalyst. It is shown that the composition of the polymers can be chosen in such a manner that the materials’ mechanical and thermal properties can be predetermined. A solvent-casting and particulate leaching scaffold preparation technique has been developed and used to create three-dimensional structures with interconnected pores. The achieved physical properties of these materials’ should facilitate their use in both soft and hard tissue regeneration.

    Well defined star-shaped polyesters have been synthesized using a spirocyclic tin initiator where L-lactide was chosen as a model system for the investigation of the polymerization kinetics. Neither the temperature nor the solvent affects the molecular weight or the molecular weight distribution of the star-shaped polymers, which all show a molecular weight distribution below 1.19 and a molecular weight determined by the initial monomer-to-initiator concentration.

  • 43.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Design of renewable polymeric materials through ring-opening reactions2018Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 256Artikkel i tidsskrift (Annet vitenskapelig)
  • 44.
    Odelius, Karin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Macromolecular design and architecture of aliphatic polyesters2008Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Public health care has reached a level where tissue or organ reconstruction by means of biodegradable short-term implants via e.g. tissue engineering will be practicable in the near future. The vital issue now is to be able to reproducibly fabricate and design new materials with the appropriate properties and three-dimensional shape, and to facilitate their sterilization. In this thesis, macromolecular design and polymer architecture techniques are used to synthesize well-defined polymers with narrow molecular weight distributions (MWD), and to control the reactions upon sterilization, and the degradation rate and profile.

    A model system for the ring-opening polymerization of L-lactide (LLA) initiated by a spirocyclic tin initiator was developed to synthesize star-shaped polymers. It was shown that an increase in temperature and a decrease in the dielectrical constant of the solvents increased the reaction rate. The versatility of the spirocyclic tin initiator system was subsequently established, by homopolymerization of ε-caprolactone (CL) and 1,5-dioxepan-2-one (DXO) and this system was compared with a conventional system using stannous octoate (Sn(Oct)2) and pentaerythritol ethoxylate. Two different strategies were assessed for the two initiator systems for the synthesis of copolymers that are random or blocky in their nature. Random copolymers with distinct sequence lengths were synthesized using both initiator systems, together with block poly(DXO-co-LLA) and poly(CL-co-LLA) with narrow MWD.

    Three different types of copolymers of LLA, CL and DXO were synthesized using Sn(Oct)2 and ethylene glycol. A solvent casting and particulate leaching technique was developed and applied to construct porous scaffolds of the copolymers. The porous scaffolds were subsequently sterilized using electron beam or γ-irradiation and it was shown that the reactions induced by radiation can be used to tailor the end-properties of the materials.

    Homo- and copolymers of CL and DXO with different macromolecular designs (triblock and multiblock) and different polymer architectures (linear and cross-linked) were synthesized and degraded in a phosphate buffer solution for up to 364 days. By altering the network composition, the release pattern of acidic degradation products was controlled, where an increase in DXO content led to an increase in the release of both monomeric hydroxy-acids. Varying the distribution of the more hydrolysis-susceptible DXO-sequences in the linear copolymers also enabled the amount of monomeric hydroxy acids released to be controlled, where the triblock copolymer showed the highest release.

  • 45.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Ring-opening reactions to functional polyamides and polyurethanes2019Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikkel i tidsskrift (Annet vitenskapelig)
  • 46.
    Odelius, Karin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Precision synthesis of microstructures in star-shaped copolymers of epsilon-caprolactone, L-lactide, and 1,5-dioxepan-2-one2008Inngår i: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 46, nr 4, s. 1249-1264Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Star-shaped homo- and copolymers were synthesized in a controlled fashion using two different initiating systems. Homopolymers of E-caprolactone, L-lactide, and 1,5-dioxepan-2-one were firstly polymerized using (I) a spirocyclic tin initiator and (II) stannous octoate (cocatalyst) together with pentaerythritol ethoxylate 15/4 EO/OH (coinitiator), to give polymers with identical core moieties. Our gained understanding of the versatile and controllable initiator systems kinetics, the transesterification reactions occurring, and the role which the reaction conditions play on the material outcome, made it possible to tailor the copolymer microstructure. Two strategies were used to successfully synthesize copolymers of different microstructures with the two initiator systems, i.e., a more multiblock- or a block-structure. The correct choice of the monomer addition order enabled two distinct blocks to be created for the copolymers of poly(DXO-co-LLA) and poly(CL-co-LLA). In the case of poly(CL-co-DXO), multiblock copolymers were created using both systems whereas longer blocks were created with the spirocyclic tin initiator.

  • 47.
    Odelius, Karin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Finne, Anna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Versatile and controlled synthesis of resorbable star-shaped polymers using a spirocyclic tin initiator: Reaction optimization and kinetics2006Inngår i: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 44, nr 1, s. 596-605Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A spirocyclic tin initiator was synthesized from pentaerythritol ethoxylate and dibutyltin oxide and used to polymerize L-lactide with dichloromethane, chloroform, toluene, and chlorobenzene as solvents. The reactions were performed at different temperatures and it is concluded that neither the temperature nor the solvent affects the molecular weight or the molecular weight distribution of the star-shaped polymers. The reaction rate was significantly increased by raising the reaction temperature or choosing a solvent with a low dielectric constant. All polymers showed a molecular-weight distribution below 1.19 and a molecular-weight determined by the initial monomer to initiator concentration ([M](0)/[1]). No induction period was seen for the polymerizations. They were all first order in initiator and the degree of aggregation in toluene at 110 degrees C was found to be 4/5. The glass transition temperature and the melting temperature of the star-shaped polymers increase with increasing arm length.

  • 48.
    Odelius, Karin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Kumar, Sanjeev
    Hakkarainen, Minna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Ghosh, Anup K.
    Bhatnagar, Naresh
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymerteknologi.
    Porosity and Pore Size Regulate the Degradation Product Profile of Polylactide2011Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 12, nr 4, s. 1250-1258Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Porosity and pore size regulated the degradation rate and the release of low molar mass degradation products from porous polylactide (PLA) scaffolds. PLA scaffolds with porosities above 90% and different pore size ranges were subjected to hydrolytic degradation and compared to their solid analog. The solid film degraded fastest and the degradation rate of the porous structures decreased with decreasing pore size. Degradation products were detected earlier from the solid films compared to the porous structures as a result of the additional migration path within the porous structures. An intermediate degradation rate profile was observed when the pore size range was broadened. The morphology of the scaffolds changed during hydrolysis where the larger pore size scaffolds showed sharp pore edges and cavities on the scaffold surface. In the scaffolds with smaller pores, the pore size decreased during degradation and a solid surface was formed on the top of the scaffold. Porosity and pore size, thus, influenced the degradation and the release of degradation products that should be taken into consideration when designing porous scaffolds for tissue engineering.

  • 49.
    Odelius, Karin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Ohlson, Madelen
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Höglund, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Polyesters with small structural variations improve the mechanical properties of polylactide2013Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 127, nr 1, s. 27-33Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Improving the properties of biodegradable polymeric materials is needed to obtain materials competitive with current bulk plastics. Low-molecular weight polyesters with small differences in their backbone were synthesized using a straight-forward method and were subsequently blended with polylactide (PLA). The materials showed an improved ductility of up to 100% points and otherwise retained material properties. The changes in mechanical properties were shown to match the miscibility range of the materials and can be predicted by the solubility parameters of the materials up to a polyester content of roughly 10% w/w. The thermal stability of all the low-molecular weight polyesters was higher than that of PLA, and most 25% w/w blends showed a thermal degradation behavior similar to that of neat PLA. Low-molecular weight polyesters were demonstrated as being potential enhancers of the properties of PLA, while the materials degradability was maintained.

  • 50.
    Odelius, Karin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Olsén, Peter G.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymerteknologi.
    Improving PLA-based material properties2012Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 244Artikkel i tidsskrift (Annet vitenskapelig)
12 1 - 50 of 76
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