One of the most important adhesives in history since the beginning of using adhesives is epoxy adhesive. Epoxy adhesives are based on epoxy resin. By changing the grade of resin and adding fillers such as metals, ceramics, etc., they show various properties. Epoxy adhesives for half a century. which are being used in the industry, have very good chemical and physical properties and are usually produced as two components (resin and hardener).
Epoxy is called epoxy resin to each of the basic components or final products treated. It is also a colloquial name for the epoxide functional group. . Epoxy resins, also known as polyepoxides. There are a group of polymers and reactive polymers that contain epoxide groups.
Epoxy resins may be synthesized by themselves via catalytic homopolymerization or with a wide range of co-reactants including polyfunctional amines, acids (and acid anhydrides), phenols, alcohols and thiols (commonly called mercaptans). ) to react. These common reactants are often called hardeners.
Classification of epoxy adhesive hardeners:
polyamines (aliphatics)
Anhydrides
Phenols
Alcohols
thiols (mercaptans)
The reaction of polyepoxides with themselves or with multipurpose hardeners is an exothermic reaction and finally forms a polymer that often has favorable mechanical properties and high thermal and chemical resistance. Epoxy has a wide range of applications, including metal coatings, use in electronics and high-pressure electrical terminals, paint brush production, fiber-reinforced plastic materials, and adhesives for structural purposes, among others.
Properties of epoxy adhesives
In general, products based on epoxy resin include a wide range of applications. Among them, we can refer to coatings and paints, adhesives and sealants that repair metal surfaces. Epoxy adhesives usually harden after drying. And their drying time varies from a few minutes to a few hours. In general, the faster the adhesives dry, the lower their final strength will be, and vice versa. One-component epoxy adhesives require heat to activate and in return have a higher drying speed than two-component epoxy adhesives.