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Bäckström, Eva
Publications (2 of 2) Show all publications
Bäckström, E., Odelius, K. & Hakkarainen, M. (2019). Designed from Recycled: Turning Polyethylene Waste to Covalently Attached Polylactide Plasticizers. ACS SUSTAINABLE CHEMISTRY & ENGINEERING, 7(12), 11004-11013
Open this publication in new window or tab >>Designed from Recycled: Turning Polyethylene Waste to Covalently Attached Polylactide Plasticizers
2019 (English)In: ACS SUSTAINABLE CHEMISTRY & ENGINEERING, ISSN 2168-0485, Vol. 7, no 12, p. 11004-11013Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
Keywords
HDPE, Oxidative degradation, Feedstock recycling, PLA, Plasticization
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-255190 (URN)10.1021/acssuschemeng.9b02092 (DOI)000472240900091 ()2-s2.0-85067031627 (Scopus ID)
Note

QC 20190904

Available from: 2019-09-04 Created: 2019-09-04 Last updated: 2019-09-04Bibliographically approved
Wu, D., Bäckström, E. & Hakkarainen, M. (2017). Starch Derived Nanosized Graphene Oxide Functionalized Bioactive Porous Starch Scaffolds. Macromolecular Bioscience, 17(6)
Open this publication in new window or tab >>Starch Derived Nanosized Graphene Oxide Functionalized Bioactive Porous Starch Scaffolds
2017 (English)In: Macromolecular Bioscience, ISSN 1616-5187, E-ISSN 1616-5195, Vol. 17, no 6Article in journal (Refereed) Published
Abstract [en]

A fully starch-derived bioactive 3D porous scaffold is developed. The bioactivity is introduced through nanosized graphene oxide (nGO) derived from starch by microwave-assisted degradation to carbon spheres and further oxidation to GO nanodots. nGO is covalently attached to starch to prepare functionalized starch (SNGO) via an esterification reaction. nGO and SNGO exhibit no cytotoxicity to MG63 at least up to 1000 µg mL−1 under (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Porous scaffolds consisting of starch and SNGO (S/SNGO) or nGO (S/nGO) are prepared by freeze drying. The porosity and water uptake ability of the scaffolds depend on the concentration of nGO. Moreover, nGO, as a bioactive nanofiller, functions as an effective anchoring site for inducing CaP recrystallization in simulated body fluid. Among all modified starch-based scaffolds, the S/SNGO scaffold containing the highest concentration of covalently attached SNGO (50%) induces the largest amount of hydroxyapatite, a type of CaP crystal that is closest to bone. The prepared 3D porous nGO functionalized scaffold, thus, exhibits potential promise for bone/cartilage tissue engineering. (Figure presented.).

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2017
National Category
Medical and Health Sciences Materials Engineering Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-208314 (URN)10.1002/mabi.201600397 (DOI)000405565300002 ()2-s2.0-85019148208 (Scopus ID)
Note

QC 20170706

Available from: 2017-06-02 Created: 2017-06-02 Last updated: 2017-11-07Bibliographically approved
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