Basic Meaning of Silicone Rubber
Silicone rubber is a high-molecular-weight elastic material with a silicon-oxygen bond main chain structure. Its molecular chain consists of alternating silicon (Si) and oxygen (O) atoms, with side chains connected to hydrocarbons or organic groups that replace hydrocarbons (such as methyl, vinyl, phenyl, etc.). This unique molecular structure endows silicone rubber with the dual properties of inorganic materials (high temperature resistance, oxidation resistance) and organic materials (such as flexibility, processability), making it an indispensable specialty rubber in modern industry.

Main Types of Silicone Rubber
1. Classification by Vulcanization Temperature
High-Temperature Vulcanizing Silicone Rubber (HTV): Requires vulcanization at 110-170℃. It has a high molecular weight (400,000-600,000) and is mainly used to manufacture seals, pipes, films, and other products. A typical example is methyl vinyl silicone rubber (VMQ), which, due to the introduction of vinyl groups improving vulcanization activity, has become the most produced and widely used variety.
Room temperature vulcanizing (RTV) silicone rubber: Cures at room temperature or with slight heating, and is divided into condensation reaction type and addition reaction type. The former uses hydroxyl-terminated polydimethylsiloxane as the base rubber, while the latter cures through a hydrosilylation reaction. It is commonly used in adhesives, potting materials, and mold making.

2. Classification by Chemical Composition
Phenyl silicone rubber (PVMQ): Introduces phenyl groups into vinyl silicone rubber, significantly improving low-temperature resistance (minimum brittle temperature reaches -120℃) and radiation resistance, suitable for spacecraft seals and high-energy radiation environments.
Fluorosilicone rubber (FMVQ): Introduces fluoroalkyl or fluoroaryl groups into the side chains, combining the heat resistance of silicone rubber with the oil resistance of fluororubber, allowing long-term contact with fuel oil, hydraulic oil, and other media at 250℃.
Nitrile silicone rubber: Contains nitrile groups (such as β-nitrile ethyl) in the side chains, exhibiting excellent oil resistance, but slightly lower heat resistance than fluorosilicone rubber, and is mostly used in special oil seal applications.