(1) High and low temperature resistance

Among all rubbers, silicone rubber has the widest working temperature range (-100 to 350 ° C). For example, a properly formulated vinyl silicone rubber or low phenyl silicone rubber can still maintain elasticity after aging at 250 ° C for thousands of hours or 300 ° C for hundreds of hours. It can maintain elasticity even after aging for one hour of hot air. Its glass transition temperature is -140 ℃, and its vulcanizate is still elastic at -70 ～ 100 ℃. Silicone rubber can withstand transient high temperatures of thousands of degrees when used as a heat-resistant coating on the inner wall of rocket nozzles.

(2) Resistance to ozone aging, oxygen aging, light aging and weathering
The silicone rubber vulcanizate has no significant change in performance after being exposed to the sun for several years in a free state.

(3) Electrical insulation properties The electrical insulation properties of silicone rubber vulcanizates change little when exposed to moisture, frequency changes, or temperature rise. The silicon dioxide generated after combustion is still an insulator. In addition, silicon rubber has few carbon atoms in the molecular structure and does not use carbon black as a filler, so it is not easy to scorch during arc discharge, and it is very reliable to use in high voltage applications. It has excellent corona resistance and arc resistance. The corona resistance life is 1000 times that of polytetrafluoroethylene, and the arc resistance life is 20 times that of fluororubber.

(4) Special surface properties and physiological inertia
The surface energy of silicone rubber is smaller than that of most organic materials. It has low hygroscopicity, and its water absorption rate is only about 1% after long-term immersion in water. The physical properties are not reduced, and the mold resistance is good. It does not adhere to many materials and can be isolated. effect. Silicone rubber is odorless, non-toxic, has no adverse effects on the human body, reacts slightly with body tissues, and has excellent physiological inertness and physiological aging.

(5) High breathability
Compared with other polymer materials, silicone rubber has good air permeability. The permeability of nitrogen, oxygen and air at room temperature is 30-40 times higher than that of NR. It has selectivity to gas permeability, such as oxygen permeability to carbon dioxide About 5 times.

(6) Biomedical properties
The characteristics of the molecular structure of silicone rubber make it have excellent biomedical properties. The successful application of a large number of animal and human experiments proves this.