Polyamide–polyurethane interpenetrating polymer networks prepared by synthesis in the melt

摘要

AbstractTwo types of interpenetrating polymer networks based on polyamide (nylon 12) and a polyurethane formed in the polyamide melt were prepared. The first type (A), which could be regarded as a semi‐2‐IPN, consisted of a polyurethane component crosslinked with trimethylolpropane whereas for the second type (B), which would meet the definition of a thermoplastic IPN, the polyurethane component was chain‐extended with butane‐1,4‐diol only. The phase morphologies of these IPNs were investigated using electron microscopy, dynamic mechanical analysis, tensile testing, and sonic velocity measurements. Electron micrographs were compared by using the conventional TEM technique and a Robinson‐type backscattered electron detector in combination with a SEM. It was concluded that the materials are phase separated, but with a fine continuous‐dispersed phase structure. For a 44 wt polyurethane IPN a cocontinuous phase structure with a subcellular texture was indicated. One physically blended sample was compared with the analogous IP