Effect of Poly(butylenes succinate) on Poly(lacticacid) Foaming Behavior: Formation of Open Cell Structure.

Biodegradable poly(lactic acid) (PLA)based poly(butylenes succinate)(PBS) foams with open cell structure were prepared via batch foamingmethod using supercritical carbon dioxide as blowing agent. It wasfound that PLA was immiscible with PBS, and PBS phase was dispersedas tiny spheres or large domains at various concentrations. The additionof PBS reduced the viscosity of the blends. During the foaming process,the PLA/PBS interfaces acted as cell nucleation sites and the lowmelt strength PBS contributed to the formation of cell connectionchannels, which resulted in open cell structure. The investigationof PBS content and foaming temperature found that PLA/PBS (80/20)foamed at 100 °C, obtaining the highest cell opening rate (96%).Two-step depressurization foaming experiments proved that bimodalcell structure PLA/PBS foams with high cell opening rate (97%) wereable to be fabricated. [ABSTRACT FROM AUTHOR]