Influence of vinyl content and its distribution
1. The vinyl content is too low, the crosslinking density of silicone rubber is small, the hardness is low, and the tear strength is low;
2. If the vinyl content is too high, the hardness of the vulcanized rubber will increase and become brittle, and the aging resistance will decrease.

In vinyl silicone oil, the effect of terminal vinyl groups and pendant vinyl groups on the performance of LSR is also different. When vinyl silicone oil has terminal vinyl groups, the crosslinking is accompanied by molecular chain growth, and the tear resistance of silicone rubber is improved.
When contains pendant vinyl groups at the same time, the cross-linking process will not only increase the molecular chain but also increase the cross-link density and further improve the physical and mechanical properties of the vulcanizate. Therefore, by choosing different vinyl silicone oils, LSRs with different properties can be obtained, and their uses are also different.

Molar mass
Vinyl silicone oil with a small molar mass can reduce the viscosity of the rubber compound, improve the fluidity, and increase the cross-linking density of the silicone rubber to a certain extent, so that it has a certain tensile strength and hardness.
Vinyl silicone oil with large molar mass can improve the elasticity and elongation at break of silicone rubber. Using vinyl silicone oil with a wide molar mass distribution can obtain silicone rubber with excellent performance.

Application
In the electronics industry, in order to improve the stability and reliability of components and the whole machine, it is often necessary to potting electronic components or assembly parts to avoid the pollution and erosion of moisture, impurities and various chemical atmospheres in the atmosphere, so that The whole machine can perform normal electrical functions stably.
- Liquid silicone rubber electronic potting glue can play the role of moisture-proof, dust-proof, anti-corrosion and shock-proof, and can improve the accuracy and stability of electronic components.
- The requirements for potting materials for electronic components are: excellent electrical properties, good insulation; excellent mechanical properties, high strength, good elasticity, low viscosity, good fluidity, and easy potting operations.

In order to ensure the electrical insulation of the potting compound, the vinyl silicone oil is required to have a small water content and low ion content. Research has found that the electrical properties of the potting compound are greatly improved after the vinyl silicone oil is refined by an adsorbent.

At the same time, in order to ensure the fluidity and mechanical properties of the potting compound, low-viscosity terminal vinyl silicone oil is often used, and when the side chain vinyl silicone oil is selected, the cross-linking points are denser and the mechanical properties are better.
  1. The vinyl groups at the two ends have strong reactivity and can react quickly with hydrogen-containing silicone oil; they can also participate in many other reactions.
  2. It has better compatibility with organic materials than methyl silicone oil, and is more compatible with other organic materials.
3. Because it contains active double bonds, it is easy to react with various organic materials such as polyurethane and acrylic.