Organosilicon, also known as siloxane or silicone, is an organopolymer formed by the cross-linking of silicon and oxygen. It possesses excellent properties such as cold resistance, heat resistance, oxidation resistance, and electrical insulation, which are not present in general organic polymers. Among these organosilicon compounds, silane coupling agents have become indispensable additives in the materials industry due to their special structural characteristics. Next, let's learn about one of the deep-processed products of organosilicon, silane coupling agents!

Introduction to coupling agent:

First, let’s briefly introduce what a coupling agent is. A coupling agent is an additive that improves the interface properties between synthetic resin and inorganic fillers in plastic compounding. It is also called an inorganic filler surface modifier. In plastic processing, it can reduce the viscosity of synthetic resin melt, improve the dispersion of fillers to improve processing performance, and thereby improve the related properties of products. Coupling agents can be divided into several categories according to their chemical composition: silane, titanate ester, aluminate ester, organic chromium (gá) complex and (gào) zirconium complex. Among them, silane coupling agent (silanecouplingagent) has the longest history. , and the most widely used.

Coupling agent molecules generally consist of two parts: one part is an inorganophilic group that can react with inorganic fillers; and the other part is an organophilic group that can interact with synthetic resins. By using coupling agents, a "molecular bridge" can be built at the interface between inorganic and organic substances to connect two materials with widely different properties, thereby improving the performance of composite materials.

Functional silanes:

Functional silanes can be divided into coupling agents and cross-linking agents according to their uses. The chemical bond connection between polymer bond segments is called cross-linking; the connection between different materials is called coupling. Common coupling agents function in organic matter and Establish compatibility between inorganic substances. The molecular structural formula of silane coupling agent is generally Y-R-Si(OR)3 (Y in the formula is an organic functional group, SiOR is a silyloxy group). The silyloxy group is reactive to inorganic substances, and the organic functional group is reactive or compatible to organic substances.

Uses of silane coupling agents

Since the development of silane coupling agents in the middle of the last century, there are hundreds of known structures. Silane coupling agents were first used in glass fiber reinforced plastics to improve the mechanical properties, electrical properties and anti-aging properties of glass fiber reinforced plastics. They are now widely used in rubber, plastics, adhesives, sealants, coatings, glass, ceramics, and metal anticorrosion field.

The largest application area of silane coupling agents is polymer composite materials. The coupling of different polymers requires different organic functional groups. The covalent bond between the silane coupling agent and the polymer can be obtained by reacting these groups with the polymer or copolymerizing the monomers.

How to use silane coupling agent 

It can be divided into vapor deposition method, solution deposition method and overall mixing method. The first two methods pretreat the surface of the substrate, so they are also called surface priming methods. The third method is mainly used for the synthesis of composites.