3-Glycidoxypropyltrimethoxysilane (IOTA-5560, CAS: 2530-83-8) is a classic epoxy-functional silane coupling agent with the molecular formula C₉H₂₀O₅Si and a molecular weight of 236.34; it appears as a colorless, transparent liquid. Featuring a trimethoxysilyl group at one end and an epoxy functional group at the other, this bifunctional structure acts as a "molecular bridge" connecting inorganic materials with organic polymers.

Upon contact with water, the trimethoxy group undergoes hydrolysis to release methanol and form silanol groups (Si-OH). These silanol groups can condense with surface hydroxyl groups on materials such as glass, silica, aluminum hydroxide, and metal oxides to form stable siloxane (Si-O-Si) bonds. Meanwhile, the epoxy group can undergo ring-opening reactions with resins such as epoxy, nylon, and PBT, enabling chemical bonding between the organic and inorganic phases.

The product is soluble in organic solvents like alcohols and acetone. Its hydrolysis products tend to self-polymerize, and the material is prone to polymerization when exposed to excessive heat, light, or peroxides; therefore, it should be stored in a sealed container in a cool, dry place. In industrial formulations, it can be added directly to the system or prepared as a hydrolyzed treatment solution to modify fillers and substrates.

It addresses the challenges of poor compatibility and weak interfacial bonding between inorganic fillers and resins, finding widespread application in the fields of composite materials, adhesives, and sealants. Treatment with IOTA-5560 significantly enhances the mechanical strength, water resistance, and electrical properties of composite materials—including superior performance retention under wet conditions—making it an indispensable additive for polymer material modification.