Selective degradation in aliphatic block copolyesters by controlling the heterogeneity of the amorphous phase
2015 (English)In: Polymer Chemistry, ISSN 1759-9954, Vol. 6, no 17, 3271-3282 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2015. Vol. 6, no 17, 3271-3282 p.
Chains, Degradation, Organic polymers, Polyesters, Thermoanalysis, Aliphatic polyester, Degradation pathways, Homogeneous composition, Monte Carlo procedures, Poly (epsiloncaprolactone), Random chain scissions, Selective degradation, Topographical images, Amorphous materials
IdentifiersURN: urn:nbn:se:kth:diva-167775DOI: 10.1039/c5py00136fISI: 000353348700010ScopusID: 2-s2.0-84928485535OAI: oai:DiVA.org:kth-167775DiVA: diva2:814170
FunderSwedish Research Council, A0347801EU, European Research Council, 246776
QC 201505262015-05-262015-05-222015-11-17Bibliographically approved