Molecularly Engineered PBATI Elastomer and Lignin-Reinforced Novel TPV with Exceptional Elasticity and Complete Biodegradability

The growing demand for sustainable alternatives to conventional thermoplastic vulcanization (TPV) has driven the need for novel biodegradable elastomers with high performance. However, existing biodegradable TPVs often suffer from insufficient elasticity and strength. This work addresses these limitations through a combined strategy of molecular engineering and lignin reinforcement. An amorphous cross-linkable PBATI elastomer was first synthesized by incorporating IPA into PBAT, disrupting chain regularity and maintaining the cross-linking property. A ternary TPV was fabricated via dynamic vulcanization, comprising PBATI as the dispersed rubber phase, PLA as the continuous matrix, and lignin as a multifunctional filler. Lignin acts as both a rigid reinforcing node and a chemical anchoring site, enhancing interfacial adhesion and inducing an interconnected PBATI network. At 10.5 wt % lignin loading, the tensile strength of TPV increases from 9.8 to 16.3 MPa, while 75% elastic recovery is maintained after 200% strain. The TPV also demonstrates stable cyclic compression behavior and a significantly reduced compression set. TPV exhibits excellent resistance to ultraviolet aging, and the biodegradation rate in natural soil within 180 days can reach over 60%. Moreover, they still maintain their original mechanical properties after multiple thermal pressing and processing cycles. This strategy provides a promising route to high-performance, fully biodegradable TPVs for sustainable applications.