In the field of composite materials and surface treatment, a class of "bridging" molecules known as silane coupling agents effectively connect inorganic materials (such as glass fibers and metal oxides) with organic polymers (such as resins and plastics), thereby significantly improving the overall performance of the materials. 2-(3,4-epoxypropoxy)propylmethyldimethoxysilane (trade name: IOTA-5563, CAS No.: 65799-47-5) is one such representative product.

IOTA-5563 is a silane coupling agent containing epoxy functional groups. Its chemical structure simultaneously possesses:

- Epoxy group: capable of undergoing ring-opening reactions with unsaturated polyesters, epoxy resins, etc., forming strong covalent bonds;

- Methyldimethoxysilyl group: hydrolyzes to generate silanol (Si–OH), which can form Si–O–M bonds with the surfaces of glass, metal oxides, etc.

Its physical properties include being a colorless, transparent liquid with a density of 1.020 g/cm³ (20℃), a boiling point of 100℃/4 mmHg, and a flash point of 105℃ (closed cup). It is soluble in alcohols, acetone, and most aliphatic solvents, but is easily hydrolyzed in water, therefore requiring strict moisture-proof storage.

Due to its dual-reactivity, IOTA-5563 is widely used in glass fiber reinforced plastics (FRP), electronic packaging materials, and coating adhesive accelerators, significantly improving the mechanical strength, electrical insulation, and resistance to damp heat aging of composite materials.