High phenyl silicone rubber refers to a high molecular weight linear polysiloxane containing phenylsiloxane or methylphenylsiloxane segments in the main chain. After mixing with fillers, organic peroxide vulcanizing agents and processing aids, it can be heated and vulcanized to become elastomers.

Introduction: When the phenyl content is more than 30%, it is generally called high phenyl silicone rubber, which has excellent radiation resistance. High molecular weight linear polysiloxane containing phenylsiloxane or methylphenylsiloxane units in the main chain. After mixing with fillers, organic peroxide vulcanizing agents and processing aids, it can be heated and vulcanized to become elastomers.

Classification: According to the phenyl content, it is divided into three types: low phenyl, medium phenyl and high phenyl.

Features: Phenyl silicone rubber has excellent low temperature resistance and ablation resistance in addition to methyl vinyl silicone rubber, which has small deformation under compression, wide operating temperature range, aging resistance, shock resistance, moisture resistance and excellent electrical insulation properties. and radiation resistance. Due to the introduction of phenyl groups into the molecular structure, the regularity of the siloxane molecular structure is destroyed, the crystallinity of the polymer is reduced, and the cold resistance is improved.

Example:
Medium phenyl silicone rubber has excellent cold resistance and can self-extinguish once it catches fire, while high phenyl silicone rubber has excellent radiation resistance. With the increase of phenyl content, the rigidity of the molecule increases, the radiation resistance and the flame resistance increase, but the cold resistance decreases. Copolymerization, the raw rubber is obtained by destroying the catalyst and removing low boilers in a vacuum, and mixing with silica and organic peroxide structure control agent on a rubber mixing machine to obtain a mixed rubber.

Uses: Processed into various products by molding and extrusion, and used as seals, gaskets, pipes and bars for low temperature, radiation and ablation resistant parts in aviation and aerospace sectors.

Features: Phenyl silicone rubber is used in applications requiring low temperature resistance and heat insulation. Medium phenyl and high phenyl silicone rubbers are difficult to process. The physical and mechanical properties are poor, and the production and application are limited. It is made by introducing diphenyl siloxane units (or methyl phenyl siloxane units) into the molecular chain of vinyl silicone rubber. This is by introducing bulky phenyl groups to destroy the regularity of the dimethylsiloxane structure and reduce the crystallization temperature and glass transition temperature of the polymer. At this time, the hardening temperature of the rubber is reduced to the lowest value (-115°C), which makes it have the best low temperature resistance and still has flexible elasticity at -100°C.