Development of in-situ nanofibrillated poly(butylene succinate)/polytetrafluoroethylene composites with elevated rheology, crystallization, and foaming performance

Herein, the nanofibrillated poly(butylene succinate)/polytetrafluoroethylene (PBS/PTFE) composites were prepared. The relaxation time was prolonged by PTFE fibrils, resulting in an enhancement in storage modulus and melt viscosity. Differential scanning calorimetry was used to study the non-isothermal crystallization kinetics at different cooling rates. These results showed that PTFE fibrils could promote crystallization nucleation and excessive fibrils could inhibit crystallization growth. Lightweight PBS/PTFE composite foams were fabricated using core-back foam injection molding. Loading the PTFE fibrils increased the cell density of PBS foam from 2.7×10⁶ to 1.4×10⁸ cells/cm³ and improved the cell morphology of PBS foam. By controlling the foaming parameter, the tensile properties of PBS-based composite foam with 1 wt.% PTFE were improved overall, and the Izod impact strength was increased by 9–69% compared with the PBS foam.