Material valorisation of amorphous polylactide. Influence of thermo-mechanical degradation on the morphology, segmental dynamics, thermal and mechanical performance
2012 (English)In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 97, no 4, 670-678 p.Article in journal (Refereed) Published
This paper reports the effects of multiple mechanical recycling on the structure and properties of amorphous polylactide (PIA). The influence of the thermo-mechanical degradation induced by means of five successive injection cycles was initially addressed in terms of macroscopic mechanical properties and surface modification. A deeper inspection on the structure and morphology of PLA was associated to the thermal properties and viscoelastic behaviour. Although FT-IR analysis did not show significant changes in functional groups, a remarkable reduction in molar mass was found by viscometry. PIA remained amorphous throughout the reprocessing cycles, but the occurrence of a cold-crystallization during DSC and DMTA measurements, which enthalpy increased with each reprocessing step, suggested chain scission due to thermo-mechanical degradation. The effect of chain shortening on the glass-rubber relaxation studied by DMTA showed an increase in free volume affecting the segmental dynamics of PLA, particularly after the application of the second reprocessing step, in connection to the overall loss of performance showed by the remaining properties.
Place, publisher, year, edition, pages
2012. Vol. 97, no 4, 670-678 p.
Polylactide (PLA), Material valorisation, Mechanical recycling, Thermo-mechanical degradation, Cold-crystallization, Segmental dynamics
IdentifiersURN: urn:nbn:se:kth:diva-81465DOI: 10.1016/j.polymdegradstab.2011.12.019ISI: 000301911300027ScopusID: 2-s2.0-84857632341OAI: oai:DiVA.org:kth-81465DiVA: diva2:497502
QC 201204232012-02-102012-02-102012-04-23Bibliographically approved