According to the molecular structure, epoxy resins can be roughly divided into glycidyl ether epoxy resins, glycidyl ester epoxy resins, glycidyl amine epoxy resins, linear aliphatic epoxy resins and cycloaliphatic ring Five categories of oxygen resin. Glycidyl ether epoxy resins are the most widely used epoxy resins in the composite industry, and among them, diphenol-based propane type epoxy resins (referred to as bisphenol A type epoxy resins) are the main ones, followed by glycidol Amine epoxy resin.
1. The glycidyl ether epoxy resin is formed by polycondensation of phenols or alcohols containing active hydrogen and epichlorohydrin, and the bisphenol A epoxy resin is formed by polycondensation of diphenol-based propane and epichlorohydrin.
2. Phenolic polyepoxy resin. It mainly includes phenol formaldehyde type and o-cresol formaldehyde type multi-epoxy resin, which is formed by polycondensation of novolak resin and epichlorohydrin. After curing, the product has large cross-link density, excellent thermal stability, mechanical properties, Electrical insulation, water resistance and corrosion resistance.
3. Other polyhydroxy phenol glycidyl ether epoxy resins have high heat distortion temperature and rigidity after curing, and can be blended alone or with general E-type resins for high-performance composite materials (ACM), printed circuit boards, etc. Matrix material. Practicability representatives include resorcinol type epoxy resin, resorcinol-formaldehyde type epoxy resin, tetraphenol ethane type epoxy resin and trihydroxyphenylmethane type epoxy resin.
4. Aliphatic polyol glycidyl ether epoxy resin. Aliphatic polyol glycidyl ether molecules contain two or more epoxy groups. Most of these resins have very low viscosities; most of them are long-chain linear molecules and are therefore flexible.