Radhika Wazalwar
A synthetic thermosetting polymer, epoxy consists of two components the resin and the curing agent. The resin provides a sufficient number of highly reactive terminal epoxide groups, and the curing agent is responsible for bonding with the resin at these epoxide groups to form a rigid cross-linked network. Epoxy resins are versatile due to their excellent mechanical, thermal, corrosion-resistant, chemical resistant and adhesive properties. As a result, epoxy composites are widely used in structural applications. Depending on the starting materials and the synthesis method, various epoxy resin types can be synthesized. Epoxy can be categorized into two families, glycidyl and non-glycidyl epoxies, which are further classified into various types. A variety of factors drives the choice of resin. Some of them are the viscosity of uncured resin, epoxy equivalent weight, curing behavior, cross-linking density, glass transition temperature (Tg), and service performance. The epoxy equivalent weight (EEW) is the ratio of the molecular weight of the epoxy monomer to the number of epoxide groups present. It is represented in terms of g/equivalent. EEW of a resin is used to calculate the amount of hardener required to achieve optimal curing in that resin. A stoichiometric or near-stoichiometric quantity of hardener should be added to the epoxy resin to achieve a good quality cured epoxy.Uncured epoxy resins are inadequate for practical applications and therefore need to be cured using a curing agent. A suitable hardening agent can be chosen depending on the type of epoxy being used and the desired end application of the epoxy composite.
