Glass fiber itself has high strength, but when directly added to resin, it is prone to interfacial debonding. This is because the glass surface has poor compatibility with organic resins.

This is where coupling agents like IOTA-570 (3-(methacryloyloxy)propyltrimethoxysilane) come in.

In glass fiber impregnation agents, IOTA-570 is typically used in conjunction with film-forming agents and lubricants to uniformly coat the glass fiber surface, forming a functionalized interfacial layer.

The treated glass fiber exhibits:
better resin wettability
stronger interfacial bonding
more stable long-term performance

In short, it transforms glass fiber from a "physical filler" into a "structural reinforcement," which is a key reason why high-performance composite materials (such as wind turbine blades and automotive parts) cannot function without silane coupling agents.