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  • 1.
    Andrén, Oliver C. J.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Walter, Marie V.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Yang, Ting
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Multifunctional Poly(ethylene glycol): Synthesis, Characterization, and Potential Applications of Dendritic-Linear-Dendritic Block Copolymer Hybrids2013In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 46, no 10, p. 3726-3736Article in journal (Refereed)
    Abstract [en]

    Emerging dendritic-linear-dendritic (DLD) hybrids that possess synergetic properties of linear and highly functional branched dendritic polymers are becoming important macromolecular scaffolds in fields ranging from biomedicine to nanotechnology. By exploiting pseudo-one-step polycondensation reactions, a facile and scalable synthetic methodology for the construction of highly functional DLDs has been developed. A library of three sets of DLDs exhibiting a hydrophilic linear PEG core with covalently attached hyperbranched bis-MPA blocks was synthesized up to the seventh generation with 256 reactive peripheral hydroxyl groups. The degree of branching for the hybrids was found between 0.40 and 0.59 with dispersities ranging from 1.03 to 1.88. The introduction of hyperbranched components resulted in control over or even full disruption of the crystallinity of the PEG. Postfunctionalizations of the peripheral hydroxyl groups with azides, allyls, and ATRP initiators yielded reactive intermediates. These intermediates were successfully assessed through UV-initiated thiol-ene coupling reactions for the synthesis of charged hybrids. ATRP of styrene from the pheriphery afforded amphiphilic macromolecules. Finally, their scaffolding capacity was evaluated for the fabrication of 3D networks, i.e, novel dendritic hydrogels and highly ordered breath figures.

  • 2.
    Antoni, P
    et al.
    KTH, Superseded Departments (pre-2005), Polymer Technology.
    Nystrom, D
    KTH.
    Malmström, Eva
    KTH, Superseded Departments (pre-2005), Polymer Technology.
    Johansson, Mats
    KTH, Superseded Departments (pre-2005), Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments (pre-2005), Polymer Technology.
    Surface modification of silica particles by controlled radical polymerization.2005In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 229, p. U963-U963Article in journal (Other academic)
  • 3.
    Antoni, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hed, Yvonne
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nordberg, Axel
    KTH, School of Technology and Health (STH), Neuronic Engineering (Closed 20130701).
    Nyström, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    von Holst, Hans
    KTH, School of Technology and Health (STH), Neuronic Engineering (Closed 20130701).
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Bifunctional Dendrimers: From Robust Synthesis and Accelerated One-Pot Postfunctionalization Strategy to Potential Applications2009In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 48, no 12, p. 2126-2130Article in journal (Refereed)
  • 4.
    Antoni, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hed, Yvonne
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nordberg, Axel
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Nyström, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    von Holst, Hans
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    One-pot dendritic growth and post-functionalization of multifunctional dendrimers: Synthesis and application2009Manuscript (preprint) (Other academic)
  • 5.
    Antoni, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Vamvounis, George
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nyström, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nyström, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Lindgren, Mikael
    Norwegian Univ Sci & Technol, Dept Phys.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Europium confined cyclen dendrimers with photophysically active triazoles2008In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 18, no 22, p. 2545-2554Article in journal (Refereed)
    Abstract [en]

    Dendrimers up to the fourth generation (G1-G4) were successfully synthesized via the efficient copper catalyzed 1,3-dipolar cycloaddition between primary alkynes and azides (CuAAC), also referred to as a click reaction. The synthetic protocol involved the preparation of presynthesized dendron wedges that subsequently were attached to a tetra-valent alkyne functional cyclen core. These constructed structures integrated stable triazole groups "intra-locked'' between the cyclen and dendron wedges. The incorporation of a lanthanide metal ion, europium, into the interior of all cyclen dendrimers was monitored by FT-IR. Interestingly, the photophysical results showed that the proximate triazole not only acts as a stable linker but also as a sensitizers, transferring its singlet-singlet excitation in the ultraviolet region (270-290 nm) to the partially filled luminescent lanthanide 4f shell. An increase of luminescence decay time from the lanthanide D-5(0) -> F-7(2) emission was observed with increasing dendrimer size, indicating that the shielding effect of the dendron wedges is important for the relaxation of the photo-excitation and energy transfer. To the best of our knowledge, this is the first time a set of dendron wedges have successfully been attached to a cyclen metal ion cage via the versatile click reaction. Furthermore, the produced triazoles intra-locked in close proximity to the macrocycle core elucidated an interesting photophysical function.

  • 6.
    Antoni, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE).
    Nystrom, Daniel
    KTH, School of Chemical Science and Engineering (CHE). KTH, Royal Inst Technol, Sch Chem Sci & Engn, SE-10044 Stockholm, Sweden..
    Hawker, Craig J.
    Univ Calif Santa Barbara, Mat Res Lab, Santa Barbara, CA 93106 USA..
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE).
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE).
    POLY 558-Synthesis of click/ester and click/ether dendrimers based on AB2-and CD2-monomers2007In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 234Article in journal (Other academic)
  • 7.
    Antoni, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nyström, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hawker, Craig
    Univ Calif Santa Barbara, Mat Res Lab.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    A chemoselective approach for the accelerated synthesis of well-defined dendritic architectures2007In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, no 22, p. 2249-2251Article in journal (Refereed)
    Abstract [en]

    A chemoselective and layered growth approach has been developed for the synthesis of dendrimers, combining Click chemistry with traditional esterification/etherification reactions, without the need for activation steps and with excellent overall yields.

  • 8.
    Antoni, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nyström, Daniel
    KTH, School of Chemical Science and Engineering (CHE).
    Ropponen, Jarmo
    KTH, School of Chemical Science and Engineering (CHE).
    Lundberg, Pontus
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Click chemistry as a tool for accelerated and one-pot synthesis of dendrimers: thermal study and application2007Manuscript (preprint) (Other academic)
    Abstract [en]

    Dendrons, dendrimers and linear polymers have been synthesized using click chemistry in combination with anhydride chemistry and atom transfer radical polymerization, ATRP. Functional materials were obtained in multigram scale using these orthogonal chemistries simultaneous.

  • 9.
    Antoni, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Robb, Maxwell J.
    Campos, Luis
    Montanez, Maria
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hawker, Craig J.
    Pushing the Limits for Thiol-Ene and CuAAC Reactions: Synthesis of a 6th Generation Dendrimer in a Single Day2010In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 43, no 16, p. 6625-6631Article in journal (Refereed)
    Abstract [en]

    Dendrimer synthesis should not be tedious and time-consuming. By utilizing an AB(2)-CD2 approach and having orthogonal, "clickable" groups on each monomer, the time for dendrimer assembly can be drastically reduced. This was shown by preparation of a sixth generation dendrimer from starting monomer units in a single day.

  • 10. Atlas, Salima
    et al.
    Raihane, Mustapha
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Lahcini, Mohammed
    Ameduri, Bruno
    Radical copolymerization of acrylonitrile with 2,2,2-trifluoroethyl acrylate for dielectric materials: Structure and characterization2013In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 51, no 18, p. 3856-3866Article, review/survey (Refereed)
    Abstract [en]

    Radical copolymerization based on acrylonitrile (AN) and 2,2,2-Trifluoroethyl acrylate (ATRIF) initited by AIBN was investigated in acetonitrile solution. The resulting poly(AN-co-ATRIF) copolymers were characterized by 1 H, 13 C, and 19 F NMR and IR spectroscopy, and size exclusion chromatography (SEC). Their compositions were assessed by 1 H NMR. The kinetics of radical copolymerization of AN with ATRIF was investigated from sereval experiments achieved at 70 degrees C from initial [AN](0)/[ATRIF](0) molar ratios ranging between 20/80 and 80/20 and was enabled to determine the reactivity ratios of both comonomers. From the monomer-polymer copolymerization curve, the Fineman-Ross and Kelen-Tudos laws enabled to assess the reactivity ratios (r(AN) = r(1) = 1.25 +/- 0.04 and r(ATRIF) = r(2) = 0.93 +/- 0.05 at 70 degrees C) while the revised patterns scheme led to r(12) = r(AN) = 1.03, and r(21) = r(ATRIF) = 0.78 at 70 degrees C. In all cases, rAN x rATRIF product was close to unity, which indicates that poly(AN-co-ATRIF) copolymers exhibit a random structure. This was also confirmed by the Igarashi's and Pyun's laws which revealed the presence of AN-ATRIF, AN-AN, and ATRIF-ATRIF dyads. The Q and e values for ATRIF were also assessed (Q(2) = 0.62 and e(2) = 0.93). The glass transition temperature values, Tg, of these copolymers increased from 17 to 61 degrees C as the molar percentage of ATRIF decreased from 77 to 16% in the copolymer. Thermogravimetry analysis of poly(AN-co-ATRIF) copolymers showed a good thermal stability compared to that of poly(ATRIF) homopolymer due to incorporation of AN comonomer.

  • 11. Busson, P.
    et al.
    Ortegren, J.
    Ihre, H.
    Gedde, Ulf W.
    KTH, Superseded Departments, Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Andersson, G.
    Ferroelectric liquid crystalline dendrimers: Synthesis, thermal behavior, and electrooptical characterization2001In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 34, no 5, p. 1221-1229Article in journal (Refereed)
    Abstract [en]

    The preparation and characterization of a series of novel ferroelectric liquid crystalline dendrimers are presented. End-capping of 1-, 2-, and 3-generation dendrimers based on 2,2-bis(hydroxymethyl)propionic acid with mesogens gave surface-functionalized liquid crystalline compounds with 6, 12, and 24 mesogen-containing units, respectively. 4 -((R)-1-Methylheptyloxy)phenyl 4-(4 '-[10(hydroxycarbonyl)decyloxyl phenyl)benzoate was synthesized and used as a mesogen-containing unit. The purity and structure of each compound were determined by H-1 NMR spectroscopy, size exclusion chromatography, and elemental analysis. Differential scanning calorimetry and optical microscopy were used to investigate the mesomorphic properties of the mesogen-functionalized dendrimers. The materials displayed a variety of mesophases, including the smectic C* phase. All the liquid crystalline dendrimers showed ferroelectricity, and tilt angle and spontaneous polarization measurements were performed. The obtained results show that the ferroelectric properties of the materials are independent of the generation number of the dendritic scaffold.

  • 12. Busson, P.
    et al.
    Ortegren, J.
    Ihre, H.
    Gedde, Ulf W.
    KTH, Superseded Departments, Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Andersson, G.
    Eriksson, A.
    Lindgren, M.
    Preparation of mesogen-functionalized dendrimers for second-order nonlinear optics2002In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 35, no 5, p. 1663-1671Article in journal (Refereed)
    Abstract [en]

    Liquid crystalline dendrimers with peripheral mesogen-containing units have been prepared. Multistep synthesis with several selective reactions was used in the preparation of the mesogen-containing molecules, 4-[10-(hydroxycarbonyl)decyloxy]phenyl 4-[4'-(2-(R)-octyloxy)-3'-nitrophenyl]benzo ate and 4-[10-(hydroxycarbonyl)decyloxy]biphenyl 4-[4'-(2-(R)-octyloxy)-3'-nitrophenyl]benzoate. Both molecules possessed an electron-accepting nitro group placed perpendicular to the long axis of the molecules in order to enhance the nonlinear optical activity. A second generation hydroxyl functional aliphatic dendrimer based on the dihydroxy acid, 2,2-bis(hydroxymethyl)propionic acid, was used as dendritic scaffold and was subsequently functionalized with the aforementioned groups. The purity and structure of the two liquid crystalline dendrimers were determined by H-1 NMR spectroscopy, size exclusion chromatography, and elemental analysis. The synthesis of both the mesogen-containing units and the liquid crystalline dendrimers is described in detail. Investigation of the liquid crystalline properties of the materials by differential scanning calorimetry and optical microscopy showed that they exhibited different mesophases, including the chiral smectic C phase. Ferroelectric switching was observed in this tilted phase, and electrooptical properties, including tilt angle and spontaneous polarization measurements, were investigated. Finally, the nonlinear optical properties of one of the materials were preliminary characterized.

  • 13.
    Carlmark, Anna
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hawker, Craig J.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    New methodologies in the construction of dendritic materials2009In: Chemical Society Reviews, ISSN 0306-0012, E-ISSN 1460-4744, Vol. 38, no 2, p. 352-362Article, review/survey (Refereed)
    Abstract [en]

    Dendritic polymers are highly branched polymer structures, with complex, secondary architectures and well-defined spatial location of functional groups. Due to their unique physical and chemical features, applications in areas such as targeted drug-delivery, macromolecular carriers, catalysis, sensors, light harvesting, surface engineering and biomimetic materials have been proposed. However, only a few dendritic materials have been exploited commercially due to time consuming syntheses and the generation of significant waste/presence of unreacted starting materials. This tutorial review describes traditional synthesis of dendritic materials as well as recent advances in synthetic strategies, for example the use of Click chemistry, as a tool to efficiently obtain complex, functional dendritic structures.

  • 14.
    Claesson, Hans
    et al.
    KTH, Superseded Departments, Polymer Technology.
    Malmström, Eva
    KTH, Superseded Departments, Polymer Technology.
    Johansson, Mats K. G.
    KTH, Superseded Departments, Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Synthesis and characterisation of star branched polyesters with dendritic cores and the effect of structural variations on zero shear rate viscosity2002In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 43, no 12, p. 3511-3518Article in journal (Refereed)
    Abstract [en]

    A series of branched polyesters consisting of poly(epsilon-caprolactone) (PCL) (degree of polymerisation: 5-200) initiated from hydroxy-functional cores and end-capped with methylmethacrylate have been prepared. The cores were third-generation hyperbranched polyester, Boltorn, with approximately 32 hydroxyl groups, a third-generation dendrimer with 24 hydroxyl groups and a third-generation dendron with eight hydroxyl groups. Finally, a linear PCL was synthesised as a reference material. All initiators were based on 2,2-bis(methylol) propionic acid (bis-MPA). C-13 NMR spectra of the polymers showed that those with shorter arms contained unreacted hydroxyl groups on the core. Rheological measurements of zero shear rate viscosity, eta(0), showed that the branched polyesters had a considerably lower eta(0) than linear polyester with similar molecular weight. The low melt viscosity and the crystallity produced a theological behaviour suitable for the film formation process for powder coatings. Measurements of mechanical properties of cured films showed that those with low arm molecular weight, M-a, were amorphous while those of high M-a were crystalline.

  • 15.
    Claesson, Hans
    et al.
    KTH, Superseded Departments, Polymer Technology.
    Malmström, Eva
    KTH, Superseded Departments, Polymer Technology.
    Johansson, Mats K. G.
    KTH, Superseded Departments, Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Doyle, M.
    Manson, J. A. E.
    Rheological behaviour during UV-curing of a star-branched polyester2002In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 44, no 1, p. 63-67Article in journal (Refereed)
    Abstract [en]

    Using a rheometer coupled with an UV-light generator, the viscoelastic behaviour during the fast cure of star-branched polyester is investigated. The 32 arm star polymers consist of a hyperbranched polyester core, Boltorn(TM) and linear grafts of poly(E-caprolactone) (degree of polymerisation: 20-52) with methacrylate end groups. The resins are crystalline and the melting points range from 34 to 50degreesC; films can be formed and cured below 80degreesC. The crossover of G' and G was used as the gel point. The time to reach the gel point, a few seconds, increases linearly with molecular weight.

  • 16.
    Claesson, Hans
    et al.
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Scheurer, Curzio
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Malmström, Eva
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Johansson, Mats K. G.
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Paulus, W.
    Schwalm, R.
    Semi-crystalline thermoset resins: tailoring rheological properties in melt using comb structures with crystalline grafts2004In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 49, no 1, p. 13-22Article in journal (Refereed)
    Abstract [en]

    Thermosetting resins with semi-crystalline grafts have been synthesized. An amorphous resin with epoxide groups was first functionalized with hydroxyl groups using 2,2-bis(methylol) propionic acid, bis-MPA in bulk at 155 degreesC. Functionalization with bis-MPA was monitored using FT-IR, FT-Raman and SEC. The reaction was complete in 30 min. Grafts of poly(epsilon-caprolactone) were then grown from the hydroxyl functional resin and end capped with methacrylate groups. The polymerization Of epsilon-caprolactone, performed in bulk at 110 degreesC using Sn(Oct)(2), was characterized using H-1 NMR and SEC. The obtained molecular weights agreed well with theoretical values. The final end capping was performed using methacrylic anhydride, and monitored with SEC and H-1 NMR, which indicated full substitution. Two combs were synthesized with different arm lengths, DP 10 and 20, and the obtained M-W were close to calculated values. The complex viscosity was measured from low to high temperature for the crystalline resins, the amorphous resin and blends thereof. Rheological data show a rapid decrease in viscosity within a temperature change of 10-15 degreesC for the crystalline resins while the amorphous resin exhibited a slow softening. The blends exhibited a behavior in-between that of the crystalline and the amorphous resin. Films were prepared from the pure resins and the blends. The films were cured using UV irradiation. The comb architecture of these resins has advantages such as crystallinity, high molecular weight and low viscosity, facilitating leveling and resulting in smooth films. The final film properties varied with the ratio of crystalline to amorphous resin, where increase in the amount of crystalline resin correlated with increased the flexibility.

  • 17. Coullerez, G.
    et al.
    Lundmark, S.
    Malkoch, Michael
    KTH, Superseded Departments, Polymer Technology.
    Magnusson, H.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Mathieu, H. J.
    Insights into ToF-SIMS analysis of dendritic macromolecules: cationization and PCA to probe their molecular weight on surfaces2003In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 203, p. 620-624Article in journal (Refereed)
    Abstract [en]

    Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is utilized to study dendrons, dendrimers and hyperbranched derivatives prepared from the 2,2-bis(hydroxymethyl)propionic acid (bis-MPA) or the 3-ethyl-3-(hydroxymethyl)oxetane (TMPO). We show that the cationization experiments of the intact molecules with alkali or metal ions such as Na+, Cu+ or Ag+ allow to detect whole molecular species up to 3000 Da (low generation). It allows to probe directly their molecular TM weight and end-functionality. However, when the molecule lift-off fails for series of hyperbranched polyesters Boltorn(TM), the fingerprint part of the SIMS spectra (m/z < 300 Da) is instead used. The low-mass fragments are mainly assigned to the bis-MP repeating unit. Ions due to the core molecule are also distinguished. Data treatment is combined with the principal component analysis (PCA) multivariate statistical method to highlight the main differences between the spectra. Only one principal component (PC1) is needed to describe most of the variance between the samples taking into account the generation effect. PC1 plotted as a function of the molecular weight gives a calibration curve. Normalization of the data set by ion intensities from the core molecule allows the linearization of the SIMS intensities vs. the molecular weight.

  • 18. Coullerez, G.
    et al.
    Lundmark, S.
    Malmström, Eva
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Mathieu, H. J.
    ToF-SIMS for the characterization of hyperbranched aliphatic polyesters: probing their molecular weight on surfaces based on principal component analysis (PCA)2003In: Surface and Interface Analysis, ISSN 0142-2421, E-ISSN 1096-9918, Vol. 35, no 8, p. 693-708Article in journal (Refereed)
    Abstract [en]

    A series of 2,2-bis(hydroxymethyl)propionic acid (Bis-MPA) hyperbranched aliphatic polyesters with different molecular weights (generations) is analysed for the first time by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The main negative and positive low-mass fragments are identified in the fingerprint part of the spectra (m/z < 400) and are principally assigned to fragmentation of the Bis-MPA repeating units. In addition, it is shown that the fragmentation pattern is highly affected by the functional end-groups. This is illustrated for a phthalic acid end-capped hyperbranched polymer and for an acetonide-terminated dendrimer analog. Also, typical fragments assigned to the ethoxylated pentaerythritol core molecule are detected. These ions show decreasing intensities with increasing molecular weight. This intensity dependency on the generation is used to calibrate the molecular weight of hyperbranched polyesters on the surface. To obtain quantitative information, a principal component analysis WCA) multivariate statistical method is applied to the ToF-SIMS data. The influence of different normalization procedures prior to PCA calculation is tested, e.g. normalization to the total intensity, to the intensities of ions assigned to the Bis-MPA repeating unit or to intensities of fragments due to the core molecule. It is shown that only one principal component (PC1) is needed to describe most of the variance between the samples. In addition, PC1 takes into account the generation effect. However, different relationships between the PC1 scores and the hyperbranched mass average molecular weights are observed depending on the normalization procedure used. Normalization of data set ion intensities by ion intensities from the core molecule allows linearization of the SIMS intensities versus the molecular weight and allows the hyperbranched polymers to be discriminated up to the highest generations. In addition, PCA applied to ToF-SIMS data provides an extended interpretation of the spectra leading to further identification of the correlated mass peaks, such as those of the Bis-MPA repeating unit (terminal, dendritic and linear) and those of the core molecule. Finally, the work presented demonstrates the extreme potential of the static ToF-SIMS and PCA techniques in the analysis of dendritic molecules on solid surfaces.

  • 19. Coullerez, G.
    et al.
    Mathieu, H. J.
    Lundmark, S.
    Malkoch, Michael
    KTH, Superseded Departments, Polymer Technology.
    Magnusson, H.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Cationization of dendritic macromolecule adsorbates on metals studied by time-of-flight secondary ion mass spectrometry2003In: Surface and Interface Analysis, ISSN 0142-2421, E-ISSN 1096-9918, Vol. 35, no 8, p. 682-692Article in journal (Refereed)
    Abstract [en]

    Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was utilized to study dendritic macromolecules with various architectures, such as dendrons, dendrimers and hyperbranched polyesters prepared from bis-(hydroxymethyl)propionic acid (Bis-MPA) and a series of hyperbranched polyethers based on 3-ethyl-3(hydroxymethyl)oxetane. The measurements were performed on spin-coated thin films of the branched molecules (D) onto silicon, chemically etched copper foil and silver-coated wafers. They showed weak signatures of molecular ions by proton capture (D + H)(+) in the high mass range of the spectra (m/z > 400). On the contrary, cationization of the intact molecules with alkali or transition metal ions such as Na+, Cu+ or Ag+ was observed. High-intensity quasi-molecular ions (D + M)(+) (with M = Na+, Cu+ or Ag+) allowed the studied polymers to be identified. The whole molecular species were observed for Bis-MPA dendrons and dendrimers up to 3000 Da for hydroxyl or acetonide-terminated derivatives. The success of the so-called cationization experiments with metal substrates compared with analysis of molecular adsorbates on silicon is highlighted. The ToF-SIMS sensitivity appeared useful to provide information about the molecular end-groups or to highlight incomplete reaction occurring during some deprotection step of the synthesis. Only uncationized fragments of low masses were detected for the hyperbranched polyesters. This result suggested the effect of molecular asymmetry and/or flattening of the molecules on the substrates, which hampered the molecule lift-off efficiency. Nevertheless, the hyperbranched polyethers were characterized based on the peak distribution of intensities, which allowed estimation of their molecular weight average. This work was intended to illustrate the capabilities of ToF-SIMS to analyse dendritic polymers on surfaces.

  • 20. Fazio, V. S. U.
    et al.
    Lagerwall, S. T.
    Busson, P.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Motschmann, H.
    Phase-matched second-harmonic generation in a ferroelectric liquid crystal waveguide2000In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 77, no 3, p. 319-321Article in journal (Refereed)
    Abstract [en]

    True phase-matched second-harmonic generation in a waveguide of crosslinkable ferroelectric liquid crystals is demonstrated. These materials allow the formation of macroscopically polar structures whose order can be frozen by photopolymerization. Homeotropic alignment was chosen which offers decisive advantages compared to other geometries. All parameters contributing to the conversion efficiency are maximized by deliberately controlling the supramolecular arrangement. The system has the potential to achieve practical level of performances as a frequency doubler for low power laser-diodes.

  • 21. Fazio, V. S. U.
    et al.
    Lagerwall, S. T.
    Zauls, V.
    Schrader, S.
    Busson, P.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Motschmann, H.
    Nonlinear optical properties of a channel waveguide produced with crosslinkable ferroelectric liquid crystals2000In: The European Physical Journal E Soft matter, ISSN 1292-8941, E-ISSN 1292-895X, Vol. 3, no 3, p. 245-251Article in journal (Refereed)
    Abstract [en]

    A binary mixture of ferroelectric liquid crystals (FLCs) was used for the design of a channel waveguide. The FLCs possess two important functionalities: a chromophore with a high hyperpolarizability beta and photoreactive groups. The smectic liquid crystal is aligned in layers parallel to the glass plates in a sandwich geometry. This alignment offers several advantages, such as that moderate electric fields are sufficient to achieve a high degree of polar order. The arrangement was then permanently fixed by photopolymerization which yielded a polar network possessing a high thermal and mechanical stability which did not show any sign of degradation within the monitored period of several months. The linear and nonlinear optical properties have been measured and all four independent components of the nonlinear susceptibility tensor (d) over bar have been determined. The off-resonant d-coefficients are remarkably high and comparable to those of the best known inorganic materials. The alignment led to an inherent channel waveguide for p-polarized light without additional preparation steps. The photopolymerization did not induce scattering sites in the waveguide and the normalized losses were less than 2 dB/cm. The material offers a great potential for the design of nonlinear optical devices such as frequency doublers of low-power laser diodes.

  • 22. Fazio, V. S. U.
    et al.
    Zauls, V.
    Schrader, S.
    Busson, P.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Lagerwall, S. T.
    Motschmann, H.
    Enhanced phase-matched second-harmonic generation in a ferroelectric liquid crystal waveguide2001In: Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, ISSN 1058-725X, Vol. 368, p. 4061-4070Article in journal (Refereed)
    Abstract [en]

    A binary mixture of crosslinkable ferroelectric liquid crystals (FLCs) was used for the design of a channel waveguide. The liquid crystal was aligned in layers parallel to the glass plates (homeotropic) in a sandwich geometry and then the arrangement was permanently fixed by photopolymerization which yielded a polar network possessing a high thermal and mechanical stability. The linear and nonlinear optical properties have been measured and all four independent components of the nonlinear susceptibility tensor d have been determined. The off-resonant d-coefficients are remarkably high and comparable to those of the best known inorganic materials. Phase-matching was achieved by taking advantage of the modal dispersion of the waveguide. A reversal of sign of chi ((2)) at the nodal plane of the electric field distribution of the first-order mode was needed to maximize the overlap. integral between the fundamental and the second-harmonic (SH) light. In samples with chi ((2)) inversion the SH Signal was 1000 larger that in samples without chi ((2)) inversion.

  • 23. Feliu, Neus
    et al.
    Walter, Marie Valérie
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Montañez, Maria I.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Kunzmann, Andrea
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Nyström, Andreas
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Fadeel, Bengt
    Stability and biocompatibility of a library of polyester dendrimers in comparison to polyamidoamine dendrimers2012In: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 33, no 7, p. 1970-1981Article in journal (Refereed)
    Abstract [en]

    Dendrimers can be designed for several biomedical applications due to their well-defined structure, functionality and dimensions. The present study focused on the in vitro biocompatibility evaluation of a library of aliphatic polyester dendrimers based on 2,2-bis(methylol)propionic acid (bis-MPA) with an overall diameter of 0.5-2 nm. In addition, dendrimers with two different chemical surfaces (neutral with hydroxyl end group and anionic with carboxylic end group) and dendrons corresponding to the structural fragments of the dendrimers were evaluated. Commercial polyamidoamine dendrimers (PAMAM) with cationic (amine) or neutral (hydroxyl) end group were also included for comparison. Cell viability studies were conducted in human cervical cancer (HeLa) and acute monocytic leukemia cells (THP.1) differentiated into macrophage-like cells as well as in primary human monocyte-derived macrophages. Excellent biocompatibility was observed for the entire hydroxyl functional bis-MPA dendrimer library, whereas the cationic, but not the neutral PAMAM exerted dose-dependent cytotoxicity in cell lines and primary macrophages. Studies to evaluate material stability as a function of pH, temperature, and time, demonstrated that the stability of the 4th generation hydroxyl functional bis-MPA dendrimer increased at acidic pH. Taken together, bis-MPA dendrimers are degradable and non-cytotoxic to human cell lines and primary cells.

  • 24.
    Fogelström, Linda
    et al.
    KTH, Superseded Departments (pre-2005), Fibre and Polymer Technology.
    Antoni, P
    KTH.
    Malmström, Eva
    KTH, Superseded Departments (pre-2005), Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments (pre-2005), Polymer Technology.
    UV-curable nanocomposite coatings.2005In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 229, p. U986-U986Article in journal (Other academic)
  • 25.
    Fogelström, Linda
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Antoni, Per
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    UV-curable hyperbranched nanocomposite coatings2006In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 55, p. 284-290Article in journal (Refereed)
    Abstract [en]

    Nanoparticles have been used to reinforce polymer matrices since the late 1980s, with promising results. Hyperbranched polymers are densely branched molecules with a globular structure, leading to lower viscosity and many end-groups, creating property-designing opportunities. Here, the two research areas, nanocomposites and hyperbranched polymers, were combined to investigate the possibility of creating a nanocomposite resin, in order to prepare a UV-curable coating system. Nanocomposites were prepared from the hyperbranched polyester Boltorn (R) H30, acrylated to 30% and 70%, and the unmodified layered silicate Na(+)montmorillonite, added both before and after the acrylation of Boltorn (R) H30. Films prepared from 30% acrylated Boltorn (R) H30 with clay added after the acrylation, having a mainly exfoliated structure according to X-ray and TEM, exhibited the largest property improvement, compared with the unfilled film. These property improvements comprised a harder surface, better scratch resistance, better adhesion to metal substrates and a small improvement in flexibility.

  • 26.
    Fogelström, Linda
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hansson, Susanne
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Linear vs. Hyperbranched Polymers in the Preparation of Polymer/Clay NanocompositesManuscript (preprint) (Other academic)
  • 27.
    Fogelström, Linda
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Johansson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hard and flexible Coatings based on Nanoparticle-filled hyperbranched Polymers2007In: Polymer Preprints, ISSN 0032-3934, Vol. 48, no 2, p. 436-437Article in journal (Refereed)
  • 28.
    Fogelström, Linda
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Johansson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hard and Flexible Nanocomposite Coatings using Nanoclay‐filled Hyperbranched Polymers2010In: ACS Applied Materials and Interfaces, ISSN 1944-8244, Vol. 2, no 6, p. 1679-1684Article in journal (Refereed)
    Abstract [en]

    The combination of hardness, scratch resistance, and flexibility is a highly desired feature in many coating applications. The aim of this study is to achieve this through the introduction of an unmodified nanoclay, montmorillonite (Na+MMT), in a polymer resin based on the hyperbranched polyester Bottom H30. Smooth and transparent films were prepared from both the neat and the nanoparticle-filled hyperbranched resins. X-ray diffraction (XRD) and transmission electron microscopy (TEM) corroborated a mainly exfoliated structure in the nanocomposite films, which was also supported by results from dynamic mechanical analysis (DMA). Furthermore, DMA measurements showed a 9-16 degrees C increase in Tg and a higher storage modulus above and below the T-g-both indications of a more cross-linked network, for the clay-containing film. Thermogravimetric analysis (TGA) demonstrated the influence of the nanofiller on the thermal properties of the nanocomposites, where a shift upward of the decomposition temperature in oxygen atmosphere is attributed to the improved barrier properties of the nanoparticle-filled materials. Conventional coating characterization methods demonstrated an increase in the surface hardness, scratch resistance and flexibility, with the introduction of clay, and all coatings exhibited excellent chemical resistance and adhesion.

  • 29.
    Fogelström, Linda
    et al.
    KTH, School of Chemical Science and Engineering (CHE).
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE).
    Johansson, Mats
    KTH, School of Chemical Science and Engineering (CHE).
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE).
    POLY 94-Hard and flexible coatings based on nanoparticle-filled hyperbranched polymers2007In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 234Article in journal (Other academic)
  • 30. Glauser, T.
    et al.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Johansson, Mats K. G.
    KTH, Superseded Departments, Polymer Technology.
    Kornmann, X.
    Berglund, Lars A.
    Toughening of electron-beam cured acrylate resins2000In: Macromolecular materials and engineering (Print), ISSN 1438-7492, E-ISSN 1439-2054, Vol. 280, no 08-jul, p. 20-25Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to improve the toughness of EB-cured acrylate thermost resins by using hyperbranched aliphatic polyesters as additives to obtain a liquid-liquid phase-separated resin. The hyperbranched polyester can be considered as a hydroxyl functional scaffold, on which functional groups were reacted by control phase separation and crosslinking. Alkyl chains of different lengths attached to the scaffold controlled phase separation. The amount of crosslinking within the rubbery particle and between the particles and the matrix was set by the percentage of methacrylate groups. A good phase separation was obtained; therefore, T-g decreased only slightly compared to the pure acrylate. The K-IC value of the cured resins was increased by 30%. The phase-separated resins showed stability with time and no significant increase in particle size was noticed after 18 months.

  • 31. Glauser, T
    et al.
    Johansson, Mats
    Hult, Anders
    Electron-beam curing of thick thermoset composite matrices1999In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 40Article in journal (Refereed)
  • 32. Glauser, T.
    et al.
    Johansson, Mats K. G.
    KTH, Superseded Departments, Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    A comparison of radiation and thermal curing of thick composites2000In: Macromolecular materials and engineering (Print), ISSN 1438-7492, E-ISSN 1439-2054, Vol. 274, no 1, p. 25-30Article in journal (Refereed)
    Abstract [en]

    This work aimed to compare three different techniques to cure thick composite matrices to see the effect of the process on the network and the thermomechanical properties of the polymer matrix. Two different thermoset resins. one acrylate and one methacrylate, have been free-radically cured with high-energy electron beam (EB), ultra-violet light (UV) ol heat (thermal). The differences in curing mechanisms as well as the thermomechanical properties of the cured resins have been investigated. For this type of resins, EB-cured samples showed the highest thermo-mechanical properties and the lowest residual unsaturation. Thermally cured resins showed similar properties, but with drawbacks such as long curing cycles and thermal degradation in the matrix. The cure did not proceed to the same extent in the UV-cured samples. But the simplicity of the curing equipment makes UV-curing an interesting complement to thermal or EB-curing.

  • 33. Glauser, T.
    et al.
    Johansson, Mats K. G.
    KTH, Superseded Departments, Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Electron-beam curing of thick thermoset composites: Effect of temperature and fiber2000In: Macromolecular materials and engineering (Print), ISSN 1438-7492, E-ISSN 1439-2054, Vol. 274, no 1, p. 20-24Article in journal (Refereed)
    Abstract [en]

    Electron-beam curing of thermoset resins used in fiber-reinforced composites has been investigated. Two resins, a bisphenol-A acrylate and methacrylate, were used as model systems. The temperature was monitored during cure to know the thermal history of the composite during cure. The thermo-mechanical properties were measured on the cured samples. It could be seen that all these values were influenced by the nature (glass or carbon) and amount (0-50 wt.-%) of fiber. A linear correlation was found between the maximum temperature during cure and the glass transition temperature. It was shown that it is possible to compensate for alack of heat during dire in systems with too low exotherms. Some influence on the network homogeneity was also noticed when the thermal energy available during cure was too low.

  • 34. Glomm, Wilhelm R.
    et al.
    Ese, Marit-Helen Glomm
    Volden, Sondre
    Pitois, Claire
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Sjoblom, Johan
    Europium(III)-cored fluorinated dendrimers at the air-water surface2007In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 299, no 03-jan, p. 186-197Article in journal (Refereed)
    Abstract [en]

    A series of lanthanide (Eu3+) cored fluorinated dendrimers of generations I through 4 (G1-G4) have been studied with respect to their film-forming properties at the air-water surface. All dendrimers studied here formed stable films at the air-water surface. At the air-water surface, the dendrimers are likely to adopt asymmetric funnel-like conformations wherein the lanthanide core is directed towards the water surface and the fluorinated phenyl groups are directed away from the bulk phase. This hypothesis was further tested by addition of an electrolyte (0.01 M MgSO4) to the subphase. The added electrolyte was found to (i) advance the onset of network formation, as well as completion of monolayers, and (ii) increase the collapse pressure. Both features support the asymmetric conformation hypothesis, in that addition of an electrolyte promotes further conformational changes and shields electrostatic repulsion between lanthanide cores, thus allowing for closer packing of the molecules.

  • 35.
    Gode, Peter
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Jannasch, Patric
    Polymer Science and Engineering, Lund University.
    Johansson, M.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Karlsson, Lina E.
    Polymer Science and Engineering, Lund University.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Sandquist, D.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    A novel sulfonated dendritic polymer as the acidic component in proton conducting membranes2006In: Solid State Ionics, ISSN 0167-2738, E-ISSN 1872-7689, Vol. 177, no 7-8, p. 787-794Article in journal (Refereed)
    Abstract [en]

    The present study involves the synthesis of sulfonated poly(3-ethyl-3-(hydroxymethyl)oxetane), sPTMPO, by end-capping the hydroxy-groups in the PTMPO with 1,4-butane sultone. A series of the polymer with different degrees of substitution was investigated. Furthermore, the subsequent use of the sulfonated PTMPO as the acidic component in proton conducting membranes was explored. The membranes were prepared by either a) mixing the partly sulfonated PTMPO with hexamethoxymethyl melamine (HMMM) to form cross-links by ether formation between the methylol groups on HMMM and the remaining hydroxyl groups on the hyperbranched polyether or b) using the sulfonated polyether in conjunction with a pyridine functionalised polysulfone, PSU-pyridine, to produce acid-base blend membranes. Membrane properties such as proton conductivity, water uptake and mechanical properties are discussed.

  • 36.
    Haraldsson, Klas Tommy
    et al.
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Johansson, Mats K. G.
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Bowman, Christopher N.
    Hult, Anders
    KTH, Superseded Departments, Fibre and Polymer Technology.
    The Effects of Hydrogen Abstraction on the Kinetics of Monofunctional Maleate/ Vinyl Ether Radical PhotopolymerizationsManuscript (Other academic)
  • 37.
    Haraldsson, Klas Tommy
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Johansson, Mats K. G.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    The Effects of Abstractable Hydrogen in Radical Photopolymerization of Maleate/Vinyl Ether Monomers Studied with EPR and Photo-RTIR2010In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 48, no 13, p. 2810-2816Article in journal (Refereed)
    Abstract [en]

    In this contribution, the influence of abstractable hydrogen on the kinetics of photopolymerized vinyl ether/maleate monomer formulations is reported. The effects of chain transfer on the polymerization rate were studied with photo real-time Infra Red (IR) for formulations composed of equimolar amounts of diethyl (DEMA) and three different vinyl ethers; methyl hexyl vinyl ether where the abstractable hydrogens adjacent to the vinyl functionality have been replaced with methyl groups, ethyl hexyl vinyl ether (EHVE) which has two easily abstractable alpha-hydrogens and triethylene glycol methyl vinyl ether (TEGMVE), which has several abstractable hydrogens. Four conclusions are drawn from these studies: (i) the vinyl ether/maleate kinetics differs significantly from the classical expression R-p = KI0.5, with recorded exponential factors of 0.84 +/- 0.04 in the absence of easily abstractable hydrogens; (ii) the presence of abstractable hydrogens significantly changes the kinetics of vinyl ether/maleate polymerizations with recorded exponential factors of 0.55 +/- 0.04 for EHVE/DEMA and 0.70 +/- 0.04 for TEGMVE/DEMA; (iii) the presence of easily abstractable hydrogens leads to a preferential consumption of maleates; and (iv) electron paramagnetic resonance studies show that vinyloxy-like radicals constitute the majority of the radicals in the systems with easily abstractable hydrogens.

  • 38. Harrisson, Simon
    et al.
    Drisko, Glenna L.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Wooley, Karen L.
    Hybrid Rigid/Soft and Biologic/Synthetic Materials: Polymers Grafted onto Cellulose Microcrystals2011In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 12, no 4, p. 1214-1223Article in journal (Refereed)
    Abstract [en]

    Rigid nanoscale polymer rods were prepared by grafting preformed amine-terminated poly(styrene) and poly(tert-butyl acrylate) onto oxidized cellulose microcrystals. Low polydispersity polymers, grown using atom transfer radical polymerization, were characterized and purified prior to cellulose attachment. Oxidation of the cellulose microcrystal led to the formation of carboxylic acids on the surface of the microcrystals. Covalent attachment of the polymers onto the cellulose microcrystals was achieved via a carbodiimide-mediated amidation reaction. The length and diameter of the polymer-cellulose composites increased upon surface modification. Typically, polymer-cellulose composites are synthesized by a grafting-from method because it can be difficult to obtain sufficient graft density using a grafting-to preparation. However, the composites reported here comprised 60-64% grafted polymer by mass. This degree of grafting-to allowed the composite to form stable suspensions in organic solvents.

  • 39.
    Hed, Yvonne
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Antoni, Per
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Montanez, Maria I.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Hult, Anders
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Malkoch, Michael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Bifunctional dendritic structures based on AB(2)C monomers2009In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 238Article in journal (Other academic)
  • 40.
    Hedenqvist, Mikael S.
    et al.
    KTH, Superseded Departments, Polymer Technology.
    Yousefi, Hamid Reza
    KTH, Superseded Departments, Polymer Technology.
    Malmström, Eva
    KTH, Superseded Departments, Polymer Technology.
    Johansson, Mats K. G.
    KTH, Superseded Departments, Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Gedde, Ulf W.
    KTH, Superseded Departments, Polymer Technology.
    Trollsas, M.
    Hedrick, J. L.
    Transport properties of hyperbranched and dendrimer-like star polymers2000In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 41, no 5, p. 1827-1840Article in journal (Refereed)
    Abstract [en]

    Moisture transport properties were assessed by sorption and desorption measurements on hydroxyl-functional hyperbranched polyesters based on 2,2-bis(methylol) propionic acid (bis-MPA) as AB(2)-monomer with ethoxylated pentaerythritol. A series of these polymers with different molar masses were studied. For the first time, it is reported that sigmoidal sorption curves were successfully modelled using a time-dependent surface boundary concentration, where the relaxation time was obtained from the mechanical stress relaxation data. The zero concentration diffusivities were very small and comparable with the values of fully amorphous poly(vinyl alcohol). Both the diffusivity data and the stress relaxation data indicated that these materials were plasticized by moisture. Ethylene glycol transport properties were measured on a hexadecanoate(C16)-terminated bis-MPA hyperbranched polymer. The replacement of the hydroxyl groups with C16 paraffin tails resulted in an increase in solute diffusivity despite the fact that these polymers became semicrystalline. The shape of the desorption curves indicated that continuous micropores were present and facilitated mass transport. The moisture transport properties were also measured on a series of semicrystalline dendrimer-like star poly(epsilon-caprolactone(s)). The low measured densities of these highly crystalline dendrimers confirmed that the porosity, as indicated by the shape of the desorption curves, had to be discontinuous. The porosity in the (C16)-terminated and the poly(epsilon-caprolactone(s)) was impossible to eliminate by applying a high external pressure during crystallization. A collective view of all the results obtained confirm that the transport properties are primarily controlled by the hydroxyl group concentration.

  • 41.
    Henriksson, Marielle
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Fogelström, Linda
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Johansson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    New nanocomposite concept based on crosslinking of hyperbranched polymers in cellulose nanopaper templates2010In: International Conference on Nanotechnology for the Forest Products Industry 2010, 2010, p. 880-897Conference paper (Refereed)
  • 42.
    Henriksson, Marielle
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Fogelström, Linda
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Johansson, Mats K. G.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Novel nanocomposite concept based on cross-linking of hyperbranched polymers in reactive cellulose nanopaper templates2011In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 71, no 1, p. 13-17Article in journal (Refereed)
    Abstract [en]

    Cellulosic fibers offer interesting possibilities for good interfacial adhesion due to the high density of hydroxyl groups at the surface. in the present study, the potential of a new nanocomposite concept is investigated, where a porous cellulose nanofiber network is impregnated with a solution of reactive hyperbranched polyester. The polymer is chemically cross-linked to form a solid matrix. The resulting nanocomposite structure is unique. The matrix surrounds a tough nanopaper structure consisting of approximately 20 nm diameter nanofibers with an average interfiber distance of only about 6 nm. The cross-linked polymer matrix shows strongly altered characteristics when it is cross-linked in the confined space within the nanofiber network, including dramatically increased T-g, and this must be due to covalent matrix-nanofiber linkages.

  • 43.
    Henriksson, Marielle
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Fogelström, Linda
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Johansson, Mats K. G.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Berglund, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    A new nanocomposites approach for strong attachment of polymer matrices to cellulose nanofibril networksManuscript (Other academic)
  • 44. Hermann, D. S.
    et al.
    Scalia, G.
    Pitois, C.
    De Marco, F.
    D'Have, K.
    Abbate, G.
    Lindgren, M.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Novel passive polymer waveguides integrated with electro-optically active ferroelectric liquid crystals2001In: Optical Engineering: The Journal of SPIE, ISSN 0091-3286, E-ISSN 1560-2303, Vol. 40, no 10, p. 2188-2198Article in journal (Refereed)
    Abstract [en]

    We report the preparation and characterization of novel isotropic polymer slab waveguides made by photochemical crosslinking, and their integration with a ferroelectric liquid crystal in an integrated electro-optic modulator. The refractive index of the passive copolymer material in the device was controlled by the copolymer composition, and good agreement between measured and calculated effective indices for the guided modes of polymer films was obtained. The active ferroelectric liquid crystal exhibited a refractive index change of Deltan approximate to0.10 upon application of an ac voltage of +/- 30 V, giving an electro-optic modulation of the input TE0-mode with a contrast ratio of 11:1 and only a small polarization conversion into TM output light.

  • 45. Hietala, Sami
    et al.
    Nyström, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Tenhu, Heikki
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Solution Properties of Dendronized Poly(Hydroxy Ethyl Methacrylate) Polymers2006In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 44, no 11, p. 3674-3683Article in journal (Refereed)
    Abstract [en]

    Four generations of dendronized polymers with a methacrylate backbone and hydroxy-functionalized aliphatic polyester dendrons based on 2,2-bis(methylol)propionic acid were studied in solutions by rheological measurements, dynamic light scattering, turbidimetry, and H-1 NMR self-diffusion measurements to reveal the effect of increasing hydrophilicity and molecular size on their solution properties. The studied polymers were interesting new amphiphiles with a hydrophobic main chain and a hydrophilic shell. Evidence of aggregation upon the heating of the first-generation polymer in an aqueous solution was obtained by dynamic light scattering and turbidimetry, reflecting the effect of the hydrophobic polymer backbone, whereas the higher generation polymers did not show aggregation upon heating. Although the dimensions of the polymers were observed to increase with increasing generation, all the polymers exhibited low viscosities and Newtonian flow behavior in both aqueous and dimethyl sulfoxide solutions. The relative viscosities of the polymers in water and dimethyl sulfoxide showed that the conformation of the polymers was somewhat more open in dimethyl sulfoxide, and this led to higher viscosities than those in water, in agreement with the H-1 NMR diffusion measurements, by which the dimensions were found to be larger for the polymers dissolved in dimethyl sulfoxide.

  • 46. Hult, Anders
    et al.
    Johansson, Mats
    Malmström, Eva
    DENDRITIC RESINS FOR COATING APPLICATIONS1995In: Macromolecular Symposia, ISSN 1022-1360, E-ISSN 1521-3900, Vol. 98Article in journal (Refereed)
  • 47. Hult, Anders
    et al.
    Johansson, Mats
    Malmström, Eva
    Hyperbranched polymers1999In: Branched Polymers II, Springer-Verlag New York, 1999, Vol. 143, p. 1-34Chapter in book (Other academic)
  • 48.
    Hult, Anders
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Larsson, Karl-Gunnar
    Method for applying a metal on a substrate2006Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    There is disclosed a method for applying a first metal on a substrate, which method comprises the steps a) producing polymers on the surface of said substrate, said polymers comprising carboxylic groups and adsorbed ions of at least one second metal, said ions being adsorbed at a pH above 7, b) reducing said ions to the second metal and c) depositing said first metal on the reduced ions of said second metal. The invention further comprises objects manufactured according to the method. Advantages of the present invention include improved adhesion of the metal coating, possibility to coat many difficult materials. The process is suitable for large-scale and continuous production and it will reduce the waste of metal. Circuits manufactured according to the invention display improved signal integrity.; Also there is the possibility to manufacture circuits which are built up sequentially with several layers of conductors in distinct patterns. It is also possible to manufacture of circuits with a very small line width.

  • 49.
    Hult, Anders
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Antoni, Per
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Dendrimers with interior and exterior functionalities comprising of azide or alkyne groups for post- functionalization by huisgen click cycloaddition2008Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    Novelty: A dendritic polymer comprising a core and repeating units, is new. Every repeating unit is bound to other unit(s) with bond(s) consisting of an ester, amide, thioether, ether, urethane, amine or imine.Use: The dendritic polymer is used for drug delivery systems, tissue engineering, data storage devices, markers for imaging, diagnostics, vaccines, phototherapeutics, optical devices, semiconductor, bioactive hydrogels and/or catalysts; for manufacture of a particle and a hydrogel (claimed); and for coatings, polyfunctional initiators for controlled radical polymerization or living free-radical polymerization techniques, ring-opening metathesis polymerization and ring-opening polymerization, dental and other composite materials, additives to control viscosity, rheology, solubility and stabilizing capacity, hybrid organic-inorganic materials, water-soluble materials, amphiphilic architectures, well-defined building blocks for precise architectural control, deposition of dendrimers on solid surfaces, dispersing agents for nanoparticles, dendrimer vehicles for encapsulation and/or delivery, and dendrimer scaffolds. The particle is used in encapsulation of low molecular compounds such as potent drugs, chelating species and fluorescent dyes.Advantage: The dendritic polymer can be functionalized both in the interior and in the exterior. It is possible to use a one-pot growth of dendritic polymer. There is provided the possibility to have more functional groups in a dendritic polymer compared to conventional polymer. When comparing the number of functional groups of a dendrimer based on A'B' x C' y -monomers with a traditional dendrimer based A'B' x -monomers, it is evident that the intrinsic functionality provides a larger number of available functional groups for post-modification. There is provided the possibility of a synthesis which is very robust, can be performed in various solvents, performed at both ambient and elevated temperatures, performed at atmospheric pressure as well as elevated, performed in a variety of gases including oxygen, nitrogen or argon. The synthesis has a high yield making the manufacture economical. There is the possibility to exclude an activation step prior to post-functionalization of a dendritic polymer. There is provided the possibility to add different types of functional groups simultaneously both to inner layer and/or to the outer layer.

  • 50. Hult, Anders
    et al.
    Malmström, Eva
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Johansson, Mats
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Sörensen, Kent
    Dendritic macromolecule, process for preparation thereof and use thereof1992Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The invention relates to a dendritic macromolecule of the polyester type comprising a central initiator molecule or initiator polymer having one or more reactive hydroxyl groups (A). The groups (A) are under formation of an initial tree structure bonded to reactive carboxyl groups (B) of a monomeric chain extender having the two reactive groups (A) and (B). The tree structure is optionally extended and further branched from the initiator molecule or initiator polymer by addition of further molecules of a monomeric chain extender by means of bonding between the reactive groups (A) and (B) thereof and is thereafter optionally further extended by reaction with a chain stopper. The invention also comprises a process for preparation of the dendritic macromolecule.

1234 1 - 50 of 154
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