Introduction to the properties and application of high tear resistance silicone rubber by gas phase method

Silicone rubber has excellent high and low temperature resistance, aging resistance, excellent dielectric properties, physiological inertia and other characteristics. It has become one of the high elastic materials indispensable to modern science and technology. The main disadvantage of silicone rubber is its strength, especially its low tear strength, which limits its application. Therefore, the necessity of improving the strength and tear resistance of silicone rubber is very important for its application.

What is the difference between high-tear silicone and ordinary silicone rubber?

The common silicone rubber compound is mainly composed of raw rubber, reinforcing filler - commonly used silica, structural control agent to prevent the interaction between silica and raw rubber, heat resistant additive - commonly used ferric oxide as a crosslinking agent peroxide.

High tear resistance silicone rubber is made of high-strength raw rubber, gradually adding modified fumed silica and other auxiliary materials. Compared with fumed silica used in ordinary fumed silica rubber, modified fumed silica has unique functional groups and higher tear strength when mixed.

What are the effects of fillers and control agents on improving tear resistance?

1. The effect of organic compounds containing vinyl on tear resistance; In order to obtain high tear resistance, the appropriate amount of vinyl silicone oil is 3-5 phr. After aging at 200 ° C * 72 hours, this compound still has excellent tear resistance; The dosage is too high, the aging performance is reduced, and the economy is also unreasonable.

2. The amount of silica has a significant effect on the tear resistance. Due to the change of the amount of silica, the amount of hydroxysilicone oil used as the structure control agent will also change; The vulcanization hardness and compression set increase with the increase of white carbon black content.

3. Through the experiment of peroxide type and dosage, it can be considered that high tear resistance silicone rubber can be prepared by using common peroxide, and the dosage range is appropriate.

4. Influence of structure control agent; Siloxane is used as the structure control agent. It is verified by experiments that no matter what kind of siloxane is used, high tear resistance can be obtained.