Enhancing Heat Resistance of PBAT Foams by Incorporating sc-PLA and In Situ Fibrillation Process

Although poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable polymer with exceptional flexibility, its broader applications are constrained by insufficient heat resistance and suboptimal mechanical qualities. To address these limitations, we used in situ fibrillation and supercritical CO2 to developed PBAT/sc-PLA composite foams with enhanced antishrinkage and heat resistance by incorporating biodegradable stereocomplexed polylactide (sc-PLA) with complementary properties. The experimental results demonstrated that the synergistic effect of sc-PLA and in situ fibrillation significantly enhanced the crystallinity, mechanical properties and heat resistance of the composites. Specifically, the in situ fibrillated composite 30LD-F exhibited a total crystallinity of 41.23%, a yield strength improvement of 128.38%, and a Vicat softening temperature of 99.8 °C. Furthermore, the 30LD-F foam displayed excellent antishrinkage with a low volumetric shrinkage of 0.39% and a heat-induced shrinkage of 29.46%. This study demonstrates that in situ fibrillated PBAT/sc-PLA composites are promising for high-performance applications requiring heat resistance and mechanical strength, such as automotive components and heat-resistant packaging.