Morphological, thermal, rheological and mechanical properties of poly (butylene carbonate) reinforced by stereocomplex polylactide.

Fully biodegradable blends of poly (butylene carbonate) (PBC) and a bioresource-based stereocomplex polylactide (sc-PLA) were prepared by melt compounding at a temperature far below the melting point (T) of sc-PLA, and above the T of PBC, poly (l-lactide) (PLLA) and poly(d-lactide) (PDLA). sc-PLA was uniformly dispersed in the PBC matrix as spherical particles. Interestingly, the size of the dispersed sc-PLA particles did not increase significantly with increasing amounts of PLLA and PDLA. sc-PLA accelerated the non-isothermal and isothermal melt crystallization of PBC. Simultaneously, the thermal decomposition temperature of the PBC/sc-PLA blends increased by about 46 °C. The solid filler sc-PLA could reinforce the PBC matrix over a relatively wide temperature range. Consequently, formation of the percolation network structure of spherical sc-PLA in the blends significantly improved the rheological and mechanical properties of PBC after incorporation of sc-PLA. This report may open a new avenue to achieve higher-performance biodegradable polymer blend materials.