3-Aminopropyltriethoxysilane CAS 919-30-2

Silane coupling agent was developed as a treatment agent for glass fiber in the early days, and its application in glass fiber reinforced composite materials has been very mature. Because the hydrolyzable group of the silane coupling agent can undergo dehydration condensation reaction with the hydroxyl group on the surface of the glass fiber after being hydrolyzed to form a stable silicon-oxygen bond; and its organic group can form a hydrogen bond or chemical bond with the resin.

Therefore, glass fibers treated with silane coupling agents can be used as reinforcing materials for most thermosetting resins and thermoplastic resins. The silane coupling agent can chemically bond resins and glass fibers with very different properties, and effectively transfer the stress of the resin to the high-strength glass fibers, thereby improving the strength of the composite material.

With the development of new varieties of silane coupling agents and the improvement of processes, silane coupling agents can enter a wider application field. Fillers for composite materials, other than fibrous fillers. There are also spherical and amorphous inorganic powder fillers. Inorganic powder fillers have the characteristics of cheap and easy to obtain, uniform particle size, etc.; but untreated inorganic powder fillers have poor compatibility and dispersibility with resins. After being treated with a silane coupling agent, the compatibility and dispersibility of the inorganic powder filler and the resin are greatly improved, and the added ratio is also increased; thus, the performance of the composite material is improved and the cost is reduced.

For example: after adding magnesium oxide to polyamide resin, its thermal conductivity is 1.16 w/(m·K); if silane coupling agent KH550 is used for surface treatment of magnesium oxide. Then the thermal conductivity of the material will increase to 2.1 W/(m·K)t. The silane coupling agent is directly added to the polymer by the overall blending method, and the thermal conductivity of the thermally conductive potting compound can be increased from 0.6 W/(m·K) to 1.0 W/(m·K)t. The former is due to the condensation reaction between the hydrolyzable groups of the silane coupling agent and the hydroxyl groups on the surface of magnesium oxide, which changes the surface of magnesium oxide from hydrophilic to hydrophobic, thereby improving the compatibility between magnesium oxide and polyamide resin. Therefore, the thermal conductivity of the composite material has a breakthrough improvement; the latter is due to the condensation reaction between the hydrolyzable group of the silane coupling agent and the hydroxyl group on the surface of the inorganic filler. Its organic group forms a chemical bond with the polymer, which acts as a bridge between the inorganic filler and the polymer, thereby improving the mechanical strength and thermal conductivity of the potting compound.

Others treated the flame retardant filler with silane coupling agent a172 or vinyltriethoxysilane (silane coupling agent a151) to make the oxygen index of the composite as high as 43%L. This is because the silane coupling agent improves its compatibility and dispersibility in the base polymer and increases the addition amount, thereby improving the flame retardancy of the composite material.

Silane coupling agents are widely used as tackifiers for adhesives, sealants, and the like. It can be used as a primer for substrates or directly added to rubber or resin by blending. Adding an appropriate amount of silane coupling agent KH570 to the adhesive (especially the acrylate adhesive) can improve the bonding effect of the adhesive to the steel.

This is because after the hydrolyzable groups in the molecule of silane coupling agent KH570 are hydrolyzed, part of the hydroxyl groups can react with the hydroxyl groups or hydroxides adsorbed on the steel surface to remove a molecule of water to form a stable chemical bond, and the remaining hydroxyl groups can be The intermolecular dehydration reaction forms a polysiloxane film on the surface of the steel; its unsaturated groups can participate in the reaction of the organic polymer to form an interpenetrating network, thereby improving the bonding strength of the adhesive and the steel.

Silane coupling agent can improve various properties of filled rubber. The effect of the amount of silane coupling agent on the vulcanization characteristics of silicone rubber was studied. It was found that the torque value of the vulcanization kinetic curve of the silicone rubber with silane coupling agent was significantly lower than that of the blank rubber compound without silane coupling agent; with the increase of the amount of silane coupling agent, the vulcanization speed increased. The slower the vulcanization time, the longer the vulcanization time, the lower the maximum torque value.