Study On Co-curing Reaction Systems For Novel Bismaleimide Resin/Epoxy Resin

Bismaleimide Resin are widely used as high-performance composite materials resin matrix because of its excellent performance. However, BMI alone as novel composite materials resin matrix had disadvantages of high cost, high melting temperature, poor solubility, cured brittle, high forming temperature and post-treatment temperature. Epoxy resin owned advantages of good adhesion, corrosion resistance, high strength and easy processing, etc., but the cured epoxy resin existed in fracture toughness and poor impact resistance, particularly, used as structural material, its maximum temperature for using is low, that largely limited its application and development. BMI and epoxy resin have good compatibility, and they are able to occur copolymerization reaction with diamine through the addition reaction to form interpenetrating network (IPN) structure, which maked curing system have higher Toughness than single component. Therefore, this article systematically studied on structure and properties of BMI/epoxy/diamine blends, expecting to obtain high-performance composite materials resin matrix, which has the great significance in studying on high performance resin system.This paper first based on phenolphthalein-based bismaleimide (PPBMI) made by oneself in the laboratory, that analysised the cure mechanism of PPBMI/Epoxy/Diamine blends by FIRT and DSC. The results showed that with increasing of temperature, the system have different curing mechanism to include epoxy cure, Michael addition between PPBMI and DDS and polymerization of residual double bonds and epoxy groups during the curing process, and studying on the curing kinetics of the blends and calculating the curing kinetic parameters to determine the proper curing process.The thermal properties of the blend systems were studied by DMA, TGA. The results showed that storage modulus, loss peak and glass transition temperature of the cure blends increased with decreasing of the content of E-51. However, glassy storage modulus and loss peak with increasing of PPBMI content, the rubbery storage modulus and glass transition temperature were correspondingly reduced. Changing of the E-51 content had little influence on the initial decomposition temperature of cured, but they were more than 390℃. Nevertheless, the high temperature thermal stability and residual carbon content rate decreased with increasing of E-51. Meanwhile, the thermal stability of cured increased with increasing of PPBMI content. Finally, the effect of E-51 and PPBMI content on the Mechanical properties and fracture morphology of copolymer were investigatied by a combination of methods such as TGA, impact strength, HDT, flexural test and SEM. Test of water absorption analysised the water absorption behavior of cure resin system. That investigatied the relationship between structures and properties. The results showed that the bending strength and modulus of cured increased with increasing of PPBMI content, while heat distortion temperature and impact strength were first increased and then decreased, with increasing of the E-51 content, the bending strength and modulus had little change, but its impact properties can be significantly improved. The morphology of impact fracture became rough and the crack became more disordered with E-51and PPBMI content increased gradually. Water absorption showed that water absorption increased with increasing of the E-51 content, and decreased with increasing of PPBMI.