Modification on phthalonitrile containing benzoxazine with hydroxy-terminated polyarylene ether nitrile: Curing reaction and thermomechanical properties

In this work, a kind of BA-ph/BPA-PEN composite film was prepared by modifying phthalonitrile resin containing benzoxazine rings (BA-ph) with hydroxy-terminated polyarylene ether nitrile resin (BPA-PEN). Results show that the introduction of BPA-PEN has a facilitating effect on the polymerization reaction of BA-ph resin, which directly affects the polymerization reaction of the benzoxazine ring and then the cross-linking reaction of the nitrile group. With the increase of BPA-PEN content, a phase reversion structure appeared, which promoted the improvement of the mechanical properties of the system. Meanwhile, the thermal performance of the system was good, and the Td5of BA-ph (2 h)/10BPA-PEN reached 342.26 °C, which was 43.13 °C higher compared with the pure BA-ph system, and the char yield at 600 °C was 71.57%.