On the toughening and crystallization behaviour of aliphatic biopolyesters

Abstract

In this doctoral thesis, two biopolyesters, polylactide (PLA) and poly(¿-caprolactone) (PCL) were studied with the aim of improving their properties and broadening their applications. The studied polymeric samples and systems were developed with two final objectives: on the one hand, improving the brittleness of PLA, which is its major drawback and main limiting factor in its applications. To that end, three different strategies were adopted: (1) the use of core-shell rubbers (CSR), (2) the addition of a soft polymer (PCL) and compatibilizers, and (3) the combined effect of the addition of a soft polymer (PCL) and a highly crystalline matrix. Moreover, the fabrication of a multi-functional system was sought through the addition of a filler. On the other hand, analysing how different intrinsic (the molecular weight and the presence of branches) and external (nucleating agents and processing conditions) factors affect the crystallization process of both PLA and PCL.