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

Although poly(butylene adipate-<i>co</i>-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.