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Preparation and characterization of stereocomplexes of PLAs/PDLA in the presence of flexible blocks

Abstract:

We studied the stereocomplex formation from homopolymers and (PLA)s/PBS multiblock copolymers to analyze the influence of the poly(butylene succinate) (PBS) flexible block on the stereocomplex formation, structure and properties. LL705.4BS307.4 and DL 706.1BS307.4copolymers presented a single crystallization process associated with PLA crystallization. On the other hand LL205.4BS807.4 and DL 20 6.1BS807.4 copolymers exhibited two crystallization processes. The IR spectrum band at 909 cm-1, associated with stereocomplex formation, was observed for stereocomplexes from homopolymercopolymer blends with a major proportion corresponding to the PLA block copolymer. DSC evidenced the difficulty of stereocomplex formation via homopolymer-copolymer mixtures with minor proportions of (PLA)s in the copolymer. Copolymer-copolymer blends were the most favored condition to stereocomplex formation from solution. ©2014 Universidad Simón Bolívar.