Enhanced Melt Memory Effects in Poly(butylene succinate) Through Incorporation of Extended-Chain Crystals

Extended-chain crystals (ECCs) of poly(butylene succinate) (PBS), featuring highly ordered molecular chains and exceptional thermal stability with a melting point 25 °C higher than conventional folded-chain crystals, demonstrate remarkable potential as nucleating agents for PBS crystallization. The incorporation of 5 wt% ECCs leads to a 12 °C increase in crystallization temperature and reduces crystallization half-time by 88% at 98 °C. Most significantly, self-nucleation studies reveal an unprecedented expansion of Domain II temperature window (∆T = 30 °C), exhibiting enhanced melt memory effects and a broadened processing window. Rheological investigations uncover the formation of unique intermolecular interactions in the melt, evidenced by non-terminal viscoelastic behavior and reduced loss tangent at elevated temperatures, with complementary evidence from higher ECC loadings confirming these findings. This local ordered structure exhibits remarkable thermal stability, persisting even above the melting point through specific intermolecular interactions, leading to the melt memory effect. These findings establish a new paradigm for nucleation control in biodegradable polyesters and provide molecular design strategies for high-performance sustainable materials.