Improvement of the interfacial properties of PBO/Epoxy composites by online continuous plasma grafting with polyurethane

Grafting modification is an effective means to improve the interfacial bonding properties of fibre composites. In this study, a series of grafted poly( p -phenylene benzobisoxazole)-polyurethane (PBO-PU) fibres were fabricated using online continuous air plasma treatment. The resulting PBO-PU fibres were characterised using attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy. The results of interlaminar shear strength (ILSS) tests show that all the PBO-PU fibre reinforced epoxy resin composites exhibited superior interfacial adhesion properties compared with the untreated composites, and the ILSS reached 48.0 MPa, indicating an improvement of 99.49 %. Our findings demonstrate that plasma grafting provides the possibility to realise industrial production of PBO/epoxy composites exhibiting high interlaminar shear strengths.