Composition of Silicone Rubber | Main Features and Uses of Silicone Rubber Products

1. What is the composition of silicone rubber?

The chemical composition of silicone rubber is silicon-oxygen. Silicone rubber means that the main chain is replaced by silicon and oxygen atoms. The silicon atom is usually connected to rubber with two organic groups. Ordinary silicone rubber is mainly composed of methyl groups and a small amount of ethylene. The introduction of phenyl can improve the high and low temperature resistance of silicone rubber, and the introduction of trifluoropropyl and cyano groups can improve the temperature and oil resistance of silicone rubber.

Silicone rubber has excellent low temperature resistance and can generally still work at -55 °C. After the introduction of phenyl, it can reach -73℃. The heat resistance of silicone rubber is also very prominent. It can work for a long time at 180 °C, and it can withstand a few weeks or longer even if it is slightly higher than 200 °C. It can withstand high temperatures above 300 °C in an instant.

Silica gel is a kind of silicone rubber. It belongs to one-component room temperature vulcanized liquid rubber. Once exposed to the air, the silane monomers in the middle will condense to form a network structure. The system is cross-linked, cannot be melted and dissolved, and is elastic. In a rubbery state, they bond objects together. Its thermal conductivity is slightly higher than that of ordinary rubber. Once cured, it is difficult to separate the bonded objects. If it is called according to some chemical books, "silica gel" should be a condensate of silicon dioxide, which is classified as an amorphous substance. Insoluble water and any solvent, non-toxic and tasteless, chemically stable, does not react with any substances except strong alkali and hydrofluoric acid.

2. Main features and uses of silicone rubber products

Silicone rubber product silicone tube is based on methyl vinyl silicone rubber, adding various fillers (reinforcing agent, heat-resistant agent, modifier, etc.) It is made by production processes such as extraction and bonding. Vulcanized rubber products have the following characteristics:

(1) High and low temperature resistance: it can be used for a long time at 200°C, and still elastic at -60°C;

(2) Electrical insulating properties: The dielectric properties of silicone rubber are excellent, especially at high temperature, which greatly exceeds that of general organic rubber, and the dielectric strength is hardly affected by temperature in the range of 20-200 °C.

(3) Excellent weather resistance, ozone resistance and ultraviolet radiation resistance, and no cracking occurs when used outdoors for a long time. It is generally believed that silicone rubber can be used outdoors for more than 20 years.

(4) Excellent high temperature compression set.

(5) With the advantages of good processing performance and easy molding, various products can be produced by extrusion hot air vulcanization molding, mold addition molding, and extension molding.

Due to its excellent comprehensive performance and good technical and economic effects, silicone rubber products have been widely used in various fields of aviation, aerospace, atomic energy, electrical appliances, electronics, instruments, automobiles, machinery, metallurgy, chemical industry, medical and health care, and daily life.