Base polymer

The following two linear polysiloxane containing vinyl groups are used as the base polymers for the addition of liquid silicone rubber. Their molecular weight distribution is wide, generally from thousands to 100,000-200,000. The most commonly used base polymer for additive liquid silicone rubber is α,ω -divinylpolydimethylsiloxane. It was found that the molecular weight and vinyl content of basic polymer could change the properties of liquid silicone rubber.

Crosslinking agent

The crosslinking agent used for adding molding liquid silicone rubber is the organic polysiloxane containing more than 3 Si-H bonds in the molecule, such as linear methyl-hydropolysiloxane containing Si-H group, ring methyl-hydropolysiloxane and MQ resin containing Si-H group. The most used is linear methyl hydrogen polysiloxane, the study found that the changing structure of the hydrogen content of crosslinking agent, or you can change the mechanical properties of silicone rubber, compared the different structure and content of crosslinking agent (containing hydrogen silicone oil) on the influence of molding liquid silicone rubber performance, found that the hydrogen content of crosslinking agent than directly with the tensile strength and hardness of the silicone rubber.

catalyst

In order to improve the catalytic efficiency of the catalysts, platinum - vinyl siloxane complex, platinum - alkyne complex and nitrogen-modified platinum complexes were prepared. In addition to the type of catalyst, its amount will also affect the performance of liquid silicone rubber products. After studying the effect of the amount of platinum catalyst on the properties of silicone rubber, it was found that increasing the concentration of platinum catalyst could promote the cross-linking reaction between methyl groups and inhibit the decomposition of main chain.

Reaction inhibitor

The mass ratio of alkynyl alcohol inhibitor to platinum catalyst affects the non-isothermal curing kinetics of liquid silicone rubber. The higher the mass ratio of alkynyl alcohol inhibitor to platinum catalyst, the higher the vulcanization characteristic temperature of the liquid silicone rubber system. Alkoxy silanized alkynes are silohydrogen addition inhibitors, which can not only prolong the coking time of the liquid silicone rubber, but also make the surface of sulfide smoother. The liquid addition silicone rubber has the effect of prolonging the inhibition time, shortening the curing time, significantly increasing the torque and faster curing speed.