2-Hydroxyethyl Methacrylate

2-Hydroxyethyl Methacrylate (CAS 868-77-9), commonly known as HEMA, is a hydroxyl-functional methacrylate monomer used to introduce reactive sites into polymer networks. Its pendant hydroxyl group enables controlled crosslinking, adhesion promotion, and compatibility with a broad range of resin systems across coatings, adhesives, and structural composites.

In UV- and peroxide-cured coatings, HEMA acts as a reactive diluent and crosslinking co-monomer, improving film hardness and adhesion to metal and plastic substrates. It enhances chemical resistance in automotive and industrial finishes. Adhesive and sealant formulators incorporate it into acrylic and methacrylate systems where hydroxyl functionality supports bonding.

This includes difficult substrates such as composites used in aerospace structures. Electronics manufacturers use HEMA-based resins in conformal coatings and encapsulants where controlled cure profiles are critical. In construction, it contributes to polymer-modified mortars and structural bonding adhesives where durability under mechanical and environmental stress is required for long-term performance.

HEMA is supplied as a clear liquid, typically with an inhibitor added to prevent premature polymerization during storage and transport. Standard commercial grades are available for industrial use. Purity levels are commonly at 97% or higher. Technical and high-purity grades are offered depending on end-use sensitivity, particularly for electronics and optical applications.