The main chain of the silicone rubber (SR) raw rubber molecule is composed of Si-O bonds, and the side groups are mainly methyl groups. Depending on the type of silicone rubber, some methyl groups can also be substituted by groups or atoms such as vinyl, phenyl or fluorine. The end groups can be methyl or hydroxyl, and the like.

There are many ways to classify silicone rubber. Here are four main classifications:
1. According to the vulcanization temperature, it can be divided into room temperature vulcanized silicone rubber and high temperature vulcanized silicone rubber;
2. According to the form before curing, it can be divided into solid silicone rubber and liquid silicone rubber (this is also what this article wants to focus on);
3. According to the difference of the monomers used, it can be divided into methyl vinyl silicone rubber, methyl phenyl vinyl silicone rubber, fluorosilicone, nitrile silicone rubber, etc.;
4. According to the different properties and uses of silicone rubber, it can also be divided into general type, ultra-low temperature resistance type, ultra high temperature resistance type, high strength type, oil resistance type, medical type, etc.

Liquid silicone rubber (LSR) is an elastomer that is vulcanized and cross-linked in the atmosphere or under heating with a small amount of water as an initiator or platinum as a catalyst. It is divided into one-component and two-component ( According to the type of reaction, it can be divided into condensation type or addition type liquid silicone rubber. Liquid silicone rubber does not contain any stabilizers, plasticizers or accelerators, and as a cross-linking material, it can withstand very high temperatures without thermal aging and can maintain its mechanical properties and elasticity. By altering certain pendant groups on it, modification of the material to meet specific functions or requirements can be achieved. LSR has excellent chemical resistance, oil resistance and weather resistance, can be stable in the temperature range of 50 ℃ to 180 ℃, can be stable at temperatures above 250 ℃ after adding stabilizers, and can be stable at -60 ℃ has low temperature flexibility. LSR is usually transparent, other pigments can be added as required, and it is very easy to color. It is widely used in electronic component sealing, pipe sealing, medical equipment, keyboards and baby related products. The application of liquid silicone rubber in the fields of 3D printing, waterproofing, coating, food contact silicone and wearable parts has great potential for development. Of course, the application in the automotive industry has also achieved a full range of coverage, such as connectors in the automotive industry, electric vehicle battery seals, engine gaskets, headlight seals and shock absorbers, etc. and the material of choice for protecting interior application solutions.