Advantages of epoxy adhesives：
① Epoxy resin contains a variety of polar groups and highly active epoxy groups, so it has strong adhesion to metals, glass, cement, wood, plastics and other polar materials, especially materials with high surface activity. At the same time, the cohesive strength of the epoxy cured product is also very large, so its bonding strength is very high.
②There is basically no low-molecular-weight volatiles produced when epoxy resin is cured. The volume shrinkage of the adhesive layer is small, about 1% to 2%, which is one of the varieties with the smallest curing shrinkage in thermosetting resins. After adding filler, it can be reduced to less than 0.2%. The coefficient of linear expansion of epoxy cured products is also very small. Therefore, the internal stress is small, and the influence on the bonding strength is small. In addition, the creep of the epoxy cured product is small, so the dimensional stability of the adhesive layer is good.
③ There are many varieties of epoxy resins, curing agents and modifiers. Through reasonable and ingenious formula design, the adhesive can have the required manufacturability (such as rapid curing, room temperature curing, low temperature curing, water curing, low viscosity, high Viscosity, etc.), and has the required performance (such as high temperature resistance, low temperature resistance, high strength, high flexibility, aging resistance, electrical conductivity, magnetic conductivity, thermal conductivity, etc.).
④It has good compatibility and reactivity with various organic substances (monomers, resins, rubbers) and inorganic substances (such as fillers, etc.), and is easy to modify by copolymerization, crosslinking, blending, filling, etc. layer performance.
⑤Good corrosion resistance and dielectric properties. It can resist the corrosion of various media such as acid, alkali, salt, solvent, etc. The volume resistivity is 1013-1016Ω·cm, and the dielectric strength is 16-35kV/mm.
⑥Universal epoxy resins, curing agents and additives have many origins, large output, simple preparation, contact pressure molding, and large-scale application.
Epoxy Adhesive Disadvantages：
①When not toughened, the cured product is generally brittle, with poor peeling resistance, crack resistance and impact resistance.
②Low adhesion to materials with low polarity (such as polyethylene, polypropylene, fluoroplastics, etc.). Surface activation treatment must be carried out first.
③Some raw materials such as reactive diluents and curing agents have different degrees of toxicity and irritation. When designing the formula, it should be avoided as much as possible, and ventilation and protection should be strengthened during construction operations.
