3-Glycidyl etheroxypropylmethyldiethoxysilane, as a representative silane coupling agent, has a very ingenious working principle. It acts like a "molecular bridge," connecting organic materials at one end and inorganic materials at the other, thus achieving a tight bond between two materials with vastly different properties.

The specific mechanism of action can be divided into two key steps:

1. **Hydrolysis Reaction**: The ethoxy group (-OC2H5) in the silane molecule hydrolyzes in the presence of water to generate a silanol group (-SiOH). This process is usually completed before use through pre-hydrolysis or on-site hydrolysis in the application system.

2. **Coupling Effect**: The silanol group generated by hydrolysis can undergo a condensation reaction with the hydroxyl groups on the surface of inorganic materials (such as glass and metal oxides) to form a stable Si-O-M chemical bond; simultaneously, the epoxy groups in the molecule can undergo a ring-opening reaction with organic polymers (such as epoxy resins and polyurethanes) to form a strong chemical bond.

This dual reaction mechanism enables 3-glycidyl etheroxypropylmethyldiethoxysilane to form strong chemical bonds at the composite material interface, significantly improving the overall performance of the material. Compared with physical mixing, this chemical bonding method can more effectively transfer stress and prevent interfacial delamination, thereby greatly improving the service life and reliability of the composite material.