In-Situ Microfibrillated Pebax/PTFE Composites with Enhanced Crystallization Kinetics, Rheological Properties, and Foaming Ability

In-situ fiberization of polytetrafluoroethylene (PTFE) can enhance the foaming performance of polymers, but due to the low melt strength and apparent viscosity of polyether block amide (Pebax), it is challenging to construct PTFE fibers in situ in the Pebax matrix. In this article, Pebax/PTFE composites with excellent tensile properties and good thermal stability were successfully prepared through the synergistic effect of in situ fiber formation and chain extension. PTFE fibers improved the rheological properties and crystallization performance of Pebax, promoted heterogeneous nucleation of cells, and prepared Pebax/PTFE foams with an average cell size as low as 5 μm and a maximum cell density of 5.9 × 10 9 cells/cm 3 . When the content of PTFE fiber is 1 wt %, the compression properties of Pebax/PTFE foam at 25 and −15 °C are up to 1.27 and 2.91 MPa respectively, which improves the competitiveness of Pebax in the application of high-end sports shoes.