The most common epoxy resins are based on the reaction of epichlorohydrin with bisphenol A. This reaction transforms the building blocks into a different chemical called bisphenol A diglycidyl ether, which is a low molecular weight resin more commonly known as BADGE or DGEBA. Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers that contain epoxy groups.
The epoxy functional group is also collectively referred to as epoxy. The IUPAC name for an epoxide group is oxirane. Epoxy, also known as polyepoxide, is a polymer used to create protective coatings, fillers, and scratch resistant adhesive products for a variety of applications. epoxy resin is viscous when in liquid form, cures quickly and adheres to a wide range of substrate materials, such as wood, metal, glass, concrete and stone.
In its most basic form, epoxy is composed of a liquid epoxy resin and a chemical hardener that cures the resin in hardened plastic. Once hardened, epoxy is extremely strong, dimensionally stable and resistant to chemicals. Epoxy is an organic compound formed by carbon chains attached to other elements such as hydrogen, oxygen or nitrogen. This bond occurs through a covalent bond, in which the elements share a pair of electrons to stay together.
The ability of this ring to react in several ways and with a variety of reagents gives epoxy resins their great versatility. The chemistry of most curing agents currently used with epoxy resins is based on polyaddition reactions that result in coupling and crosslinking. The most widely used curing agents are active hydrogen-containing compounds (polyamines, polyacids, polymercaptans, polyphenols, etc. Since their introduction in the 1940s, epoxies have been essential for a wide variety of industries and applications.
Epoxy resins generally require a precise blend of two components that form a third chemical to obtain the indicated properties. The resulting material has ether bonds and shows greater chemical and oxidation resistance than that typically obtained by curing with amines or anhydrides. Epoxy resins (also widely known as epoxy resins and occasionally as ethoxylin resins) are characterized by the possession of more than one 1,2-epoxy group (I) per molecule. The most common epoxy resins are based on the reaction of epichlorohydrin (ECH) with bisphenol A, resulting in a different chemical known as diglycidyl ether of bisphenol A (commonly known as BADGE or DGEBA).
Epoxies are sold in hardware stores, usually as a separate package containing resin and hardener, which must be mixed immediately before use. When cured, epoxy resin results in a thermosetting plastic with high chemical resistance and low water absorption. Many properties of epoxies can be modified (for example, silver-filled epoxies with good electrical conductivity are available, although epoxies are typically electrical insulators). Paul Schlack from Germany first reported and patented the condensation of epoxides and amines in 1934.Insufficient heat during curing will result in a network with incomplete polymerization and, therefore, lower mechanical, chemical and thermal resistance.
The reaction of polyepoxides with themselves or with polyfunctional hardeners forms a thermosetting polymer, often with favorable mechanical properties and high thermal and chemical resistance. Due to the presence of significant polarity, epoxies wet and adhere exceptionally well to many surfaces. A later Castan3 patent covered the curing of epoxy resins with alkaline catalysts used in the range of 0.1 to 5%. This patent, however, acquired a somewhat restricted value, since important amine hardeners are generally used in quantities greater than 5%.
The chemistry of epoxies and the range of variations available on the market make it possible to produce curing polymers with a very wide range of properties. In the early 1980s, global epoxy resin capacity reached approximately 600,000 tons per year, but at this time plant utilization was only 50 to 60%. . .
