Preparation of SIC hybrid phenolic resin composites

Organic-inorganic hybrid materials consisting of inorganic materials and organic polymers are a new class of materials, which have received much attention in recent years. This kind of materials exhibit characteristics of both inorganic materials and organic polymers. It has been established in recent years that polymer reinforced with a small percentages of strong fillers can significantly improve the mechanical and thermal properties. Because of the strong attraction between the particles and the limited shear forcé during compounding, inorganic particles are easy to agglomerate, so it is very difficult to be uniformly dispersed in polymers. SiC particles can be chemically modified by introducing grafting polymers onto the surface of the tiny particles not only outside but also inside the particle agglomerates. This is owing to the low molecular weight nature, the monomers can penetrate into the agglomerated particles easily and react with the activated sites of the particles. The interstitial volume inside the particle agglomerates is partly filled with grafting macromolecular chains, and the agglomerated particles are further separated. The author took SiC ceramic as the inorganic component, which has a lot of excellent properties, such as high hardness, excellent mechanical strength at high temperature, better resistance to creep, high oxidation and chemical corrosion resistance, low coefficient of thermal expansion, high resistance to wear and low abrasion coefficient, high thermal conductivity and so on. First, the surface modification of SiC was carried out with coupling agent, then grinded it to fine powder, and added it to phenolic resin during the polymerization process, finally got SiC hybrid phenolic resin composites. The material was characterized with thermogravimetry(TG) and scanning electron microscope(SEM) techniques. After performance testing of the material, it was found that heating 1 hour at 400°C, weight loss of the composite which contained 5wt% of SiC was 4.00%, while heating 1 hour at 500°C, weight loss of the composite was 6.31%. But at 500°C, weight loss of pure phenolic resin by TG was 60.53%. In order to improve the mechanical performance of the hybrid material, glass fiber was used as the reinforcement.