(1) High mechanical properties. Epoxy resin has strong cohesion and compact molecular structure, so its mechanical properties are higher than general thermosetting resins such as phenolic resin and unsaturated polyester.
(2) Excellent bonding performance. The extremely active epoxy group, hydroxyl group, ether bond, amine bond, ester bond and other polar groups in the epoxy resin curing system give the epoxy cured product extremely high bonding strength. In addition, it has high cohesive strength and other mechanical properties, so its bonding performance is particularly strong and can be used as a structural adhesive.
(3) The curing shrinkage rate is small. It is generally 1% to 2%. It is one of the varieties with the smallest curing shrinkage rate among thermosetting resins (phenolic resin is 8% to 10%; unsaturated polyester resin is 4% to 6%; silicone resin is 4% to 8%). The coefficient of linear expansion is also very small, generally 6×10-5/℃. Therefore, the product has stable dimensions, low internal stress, and is not easy to crack.
(4) Good manufacturability. The epoxy resin basically does not produce low molecular volatiles when it is cured, so it can be molded under low pressure or contact pressure. The formula design has great flexibility, and formulas suitable for various process requirements can be designed.
(5) Good electrical performance. It is one of the varieties with the best dielectric properties among thermosetting resins.
(6) Good stability. Epoxy resin without impurities such as alkali and salt is not easy to deteriorate. As long as it is stored properly (sealed, protected from moisture, and exposed to high temperature), its storage period is 1 year. After the expiration date, it can still be used if the inspection is qualified. The epoxy cured product has excellent chemical stability. Its corrosion resistance to various media such as alkali, acid and salt is better than thermosetting resins such as unsaturated polyester resin and phenolic resin.
(7) The heat resistance of epoxy cured products is generally 80-100°C. The heat-resistant varieties of epoxy resin can reach 200℃ or higher.
(8) Among the thermally lying resins, epoxy resin and its cured products have the best overall performance.