Preparation of an environmentally friendly water-soluble sizing agent and its application in CF/PPESK composites

In this study, a series of high temperature resistant water-soluble thermoplastic sizing agents were designed and synthesized to improve the interfacial bonding of CF/PPESK composites. The effects of the ratio of water-soluble functional monomer (PPL) and high temperature resistant monomer (DHPZ) on the performance of the pastes were investigated. The results showed that the sizing agent with PPL: DHPZ = 6: 4 had the best performance, and its thermal decomposition temperature was up to 348 °C, which met the requirements of the composite molding process. The ILSS and flexural strength reached the peaks of 67.2 MPa and 1526.5 MPa. The retention rates were 89.7 % and 81.8 %, respectively, after hydrothermal aging treatment, compared with 77.7 % and 79.2 % for the epoxy sizing agent. The bottleneck of traditional epoxy sizing agent and CF/PPESK composites molding process mismatch has been broken.