Coupling agent is an important and increasingly widely used processing agent, mainly used as an additive for polymer composite materials. The biggest characteristic of the molecular structure of coupling agents is the presence of two groups with different chemical properties in the molecule. One is a group that is hydrophilic to inorganic substances and easily reacts with the surface of inorganic substances; The other is an organic group that can react chemically or form hydrogen bonds with synthetic resins or other polymers and dissolve in them. Therefore, coupling agents are called "molecular bridges" to improve the interfacial interaction between inorganic and organic materials, thereby greatly enhancing the properties of composite materials, such as physical, electrical, thermal, and optical properties.
Coupling agents were first used as surface treatment agents for glass fibers in glass fiber reinforced plastics. Later, they were widely used in rubber, plastics, coatings, inks, adhesives, wires and cables, resin sand casting, abrasives, fiberglass, artificial quartz, and textiles. In recent years, they have shown excellent performance in silane treatment solutions. In fact, the amount of silane used in metal surface treatment is very small, and its content in the ceramic solution formula is basically 0.5-2%.
The naming principle of silane coupling agents is usually based on silane as the main name, followed by the names of substituents or silicon functional groups, and the positions of substituents or carbon functional groups are annotated in the prescribed order to obtain the chemical formula name of silane coupling agents. In the daily production and operation process, silane coupling agents are often used under the trade name in various occasions. Due to historical reasons, the silane industry still uses different brand systems to name products.
There are various types of coupling agents, including silane coupling agents, titanate coupling agents, aluminate coupling agents, bimetallic coupling agents, phosphate coupling agents, borate coupling agents, chromium complexes, and other coupling agents for higher fatty acids, alcohols, and esters. Currently, the most widely used are silane coupling agents and titanate coupling agents, and the most commonly used in the rubber industry are silane, titanate, and aluminate coupling agents. Silane coupling agent is the earliest researched and applied coupling agent by people.
