Recycling extrusion of poly(ether‐block‐amide) thermoplastic elastomer (Pebax®): the influence of chemical and crystal change on mechanical properties

Abstract

In this work, two poly(ether‐block‐amide) thermoplastic elastomers (Pebax® 2533 and Pebax® 5533) were subjected to five extrusion cycles. We characterized the various performance changes of the two materials after injection molding, including chemical structure, crystalline properties and mechanical properties, and also analyzed the reasons for the observed changes. Attenuated total reflectance Fourier transform infrared spectroscopy shows that, after repeated extrusion, free hydroxyl groups and new oxygen‐containing functional groups (carbonyl groups) were formed inside the materials. X‐ray photoelectron spectroscopy shows that the oxygen content of the material increased significantly. TGA shows that the thermal stability of the material was slightly improved. The elastomer melt index also increased with extrusion cycles. By analyzing the crystalline properties (DSC, XRD) of the materials, we tentatively explain the different changes in the two poly(ether‐block‐amide) thermoplastic elastomers in terms of mechanical properties. © 2021 Society of Industrial Chemistry.