According to its vulcanization mechanism, silicone rubber can be divided into three categories: hot vulcanization, room temperature vulcanization and addition reaction. Hot vulcanized rubber is mainly introduced here.

(1) High and low temperature resistance

In all rubber, silicone rubber has the widest operating temperature range (-100 ~ 350℃). For example, after appropriate coordination of vinyl silicone rubber or low phenyl silicone rubber, 250℃ for thousands of hours or 300℃ for hundreds of hours of hot air aging can still maintain elasticity; Low phenyl silicone rubber vulcanizate can still maintain elasticity after tens of hours of hot air aging at 350 deG C, its vitrification temperature is -140 DEG C, and its vulcanizate is still elastic at -70 ~ 100 DEG C. Silicone rubber can withstand thousands of degrees of instantaneous high temperature when it is used as heat resistant coating on the inner wall of rocket nozzle.

(2) ozone aging resistance, oxygen aging resistance, light aging resistance and weather aging resistance

The properties of silicone rubber vulcanizate did not change significantly after being exposed outdoors in free state for several years.

(3) Electrical insulation performance

The electrical insulation performance of silicone rubber vulcanized rubber changes little when it is affected with moisture, frequency change or temperature rise, and the silicon dioxide generated after combustion is still an insulator. In addition, the molecular structure of silicone rubber carbon atoms, and no carbon black as filler, so in the arc discharge is not easy to coke, in high pressure occasions is very reliable. Its corona resistance and arc resistance is excellent, corona resistance life is 1000 times of PTFE, arc resistance life is 20 times of fluorine rubber.

(4) Special surface properties and physiological inertia

The surface energy of silicone rubber is smaller than that of most organic materials, and it has low hygroscopicity. The water absorption rate is only about 1% when immersed in water for a long time. The physical properties do not decrease, the mildew resistance is good, and there is no bonding with many materials, which can play an isolation role. Silicone rubber is tasteless, non-toxic and has no adverse effects on human body. It has slight reaction with body tissue and excellent physiological inertia and aging.

(5) High permeability

Compared with other polymer materials, silicone rubber has good permeability, and the permeability of nitrogen, oxygen and air at room temperature is 30 ~ 40 times higher than NR. It has selectivity to gas penetration, such as the permeability of carbon dioxide is about 5 times that of oxygen.

(6) Biomedical performance

The molecular structure of silicone rubber makes it have excellent biomedical properties, which has been proved by a large number of successful applications in animal and human experiments.