Preparation of phthalonitrile resin/calcium sulfate whisker composites with enhanced wear and heat resistance

Composites based on high-performance resin matrix have excellent high temperature resistance, chemical stability, and excellent processability, and exhibit a wide range of applications in many fields. At present, there are no reports on the application of calcium sulfate whiskers (CSW) in phthalonitrile resins. In this study, KH560 was used to modify CSW, through FT-IR, TGA, XRD and XPS methods, KH560 was successfully grafted onto CSW, and the modified CSW was filled with phthalonitrile resin containing fluorine elements. SEM shows that the modified CSW is uniformly dispersed in the resin. The storage modulus of composites increased from 2.6 GPa to 3.8 GPa. Under air and nitrogen atmospheres, the T 5% of the composites increased by about 10°C. When the addition amount of CSW is 10%, the friction coefficient of the material is reduced from 0.68 to 0.58, the depth of wear marks decreased from 49.1 μm to 27.9 μm, the wear rate of AFPN-10 (the addition amount of CSW is 10%) decreases from 3.59 × 10 −4 mm 3 /(N·m) to 2.70 × 10 −4 mm 3 /(N·m), the wear resistance performance was significantly improved. With the increase of CSW in composites, the hardness, reduced modulus and elastic recovery rate are also gradually increasing, the highest reduced modulus and hardness are 2434 MPa and 597 MPa respectively. The addition of CSW can improve the mechanical properties and thermal properties of the phthalonitrile resin, as well as enhance its anti-friction ability. Phthalonitrile resin-based composites have potential application values in the fields of aerospace, electronic instruments and lightweight components.