Study On Heat-resistant Resin Binder For Superabrasives

A novel thermosetting resin for superabrasives based on novolak and bismaleimide (BMI) was developed. The novolak resin was allylated, and then copolymerized with BMI. FTIR, 1H-NMR and DSC-TG were employed to characterize the structures and properties of allyl novolak (AN) and modified BMI (AN/BMI). The results showed that only double bond of BMI reacted with double bond of allyl novolak. High molecular weight and allyl content of the novolak were advantageous for heat-resistance of AN/BMI. The decomposition of degradation of methylene and allyl group resulted in the thermal oxidative degradative of AN/BMI.SiC/AN/BMI composite was synthesized. Bending strengths of the composite before and after heat treatment were measured to characterize its mechanical properties and heat-resistance. The fracture surface of the composite and the bonding interface between SiC and AN/BMI were analyzed by scanning electron microscopy (SEM). The amount of AN/BMI in the composite, the density of molding, the molecular weight and allyl content of novolak and surface condition of grits had obvious influence on its mechanical properties. Within a certain extent, the bending strength of the composite increased with increasing AN/BMI content and density of molding. With the increasing of molecular weight and allyl content of novolak, the bending strength decreased. The bonding strength between resin and grits increased with increasing surface roughness of grits. The properties of SiC/AN/BMI were better than that of SiC/PI and SiC/PBMI made in similar process...