Silicone rubber has a variety of excellent properties, but its mechanical properties such as compressive strength and tear strength are poor and cannot meet the requirements of the process. It is necessary to add fillers to modify and strengthen it. When MQ silicone resin is used as a reinforcing filler, it can not only increase the strength of the rubber matrix, but also not increase the viscosity of the system too quickly to facilitate subsequent operations. The vulcanizate prepared has better transparency.

The organic part of the MQ silicone resin can improve its compatibility with silicone rubber and play a role in increasing viscosity; the silicone chain energy-saving improves the mechanical strength, cohesive strength, peeling strength and high temperature resistance of the silicone rubber, and plays a reinforcing role. Addition vulcanized silicone rubber is mainly composed of vinyl-containing raw rubber, reinforcing filler, hydrogen-containing silicone oil cross-linking agent, and platinum catalyst. Under the action of a platinum catalyst, a vinyl-containing MQ resin can chemically bond with raw rubber through a hydrosilylation reaction with a SiH cross-linking agent, thereby forming a three-dimensional network structure to reinforce. With the increase of the amount of MQ silicone resin, the hardness, tensile strength, tear strength, adhesive properties, and crosslinking density of silicone rubber have gradually increased to the optimum value. The reason is that the molecular weight of the MQ silicone resin is relatively small, the vinyl content is relatively high, the compatibility and dispersibility in the silicone rubber is good, and chemical bonding occurs with the silicone rubber. However, when the crosslinking density is too large, the distribution of the crosslinking points is uneven, and stress concentration is formed. The silicone rubber becomes hard and brittle, and the silicone rubber is easily broken under the stress. The curing time increases with the increase in the amount of MQ. This is because MQ molecules are small and the vinyl content is high, and they can preferentially react with hydrogen-based silicone oil, which delays the reaction of hydrosilicone and vinyl raw rubber until MQ is consumed. As the amount of MQ resin increases, the dielectric constant of silicone rubber increases to a maximum and approaches equilibrium. However, the use of MQ resin is too large, and the silicone rubber is excessively crosslinked, which limits the movement of polar groups, thereby making the dielectric constant stable. However, the dielectric properties of silicone resins are still lower than that of ordinary rubber.

The condensation type vulcanized silicone rubber is mainly composed of a silicone rubber containing a terminal hydroxyl group or an alkoxy group, a reinforcing filler, a crosslinking agent and a catalyst. After the catalyst or the action of water in the air, the cross-linking agent is hydrolyzed to form silanol, and a condensation reaction with the silanol groups of the raw rubber occurs to form a three-dimensional network structure, which is vulcanized into an elastomer. When MQ silicone resin is mixed with silicone rubber, it plays a role of increasing viscosity and strengthening, which makes silicone rubber have excellent mechanical properties. However, when it is exposed to electromagnetic radiation and vacuum ultraviolet radiation, the silicone rubber will age, deform and crack, and the performance will change accordingly. difference. The main reasons for the decrease in the quality and performance of silicone rubber due to irradiation are the escape of unreacted low-molecular substances in the vulcanizate under irradiation, the breakage of the macromolecular network structure, and the degradation or cross-linking of molecular chains. In order to make the silicone rubber resistant to radiation, a radiation-resistant filler, such as nano-TiO2, may be added thereto.