Influence of vinyl content and its distribution

1. Low vinyl content, low crosslinking density, low hardness and low tear strength of silicone rubber;

2. If the vinyl content is too high, the hardness of the vulcanizate becomes larger and brittle, and the aging resistance decreases.

In vinyl silicone oil, the effects of end vinyl and side vinyl on the properties of LSR are also different. When vinyl silicone oil with end vinyl, crosslinking is accompanied by the growth of molecular chain, and the tear resistance of silicone rubber is improved.

At the same time, when containing side vinyl, the crosslinking process can not only be accompanied by the growth of molecular chain, but also improve the crosslinking density and further improve the physical and mechanical properties of vulcanizates. Therefore, LSR with different properties can be obtained by selecting different vinyl silicone oils, and its uses are also different.

Molar mass

Vinyl silicone oil with small molar mass can reduce the viscosity of the compound, improve the fluidity, improve the crosslinking density of silicone rubber to a certain extent, and make it have certain tensile strength and hardness.

Vinyl silicone oil with large molar mass can improve the elasticity and elongation at break of silicone rubber. Silicone rubber with excellent performance can be obtained by using vinyl silicone oil with wide molar mass distribution.

application

In the electronic industry, in order to improve the stability and reliability of components and the whole machine, it is often necessary to encapsulate the electronic components or assembly parts to avoid the pollution and erosion of water vapor, impurities and various chemical atmospheres in the atmosphere, so that the whole machine can stably play normal electro pneumatic function.

Liquid silicone rubber electronic potting adhesive can play the role of moisture-proof, dust-proof, corrosion-proof and shock proof, and can improve the accuracy and stability of electronic components.

Requirements for potting materials of electronic components include: excellent electrical performance and good insulation; Excellent mechanical properties, high strength and good elasticity; Low viscosity, good fluidity, convenient for potting operation.

In order to ensure the electrical insulation of potting adhesive, vinyl silicone oil is required to have low water content and low ion content. It is found that the electrical properties of potting adhesive are greatly improved by refining vinyl silicone oil with adsorbent.

At the same time, in order to ensure the fluidity and mechanical properties of potting adhesive, end vinyl silicone oil with low viscosity is often selected, while when side chain vinyl silicone oil is selected, the crosslinking point is more dense and the mechanical properties are better.

1. Vinyl at both ends has strong reaction activity and can react with hydrogen containing silicone oil quickly; It can also participate in a variety of other reactions.

2. It has better compatibility with organic materials than methyl silicone oil and is easier to be compatible with other organic materials.

3. Because it contains active double bonds, it is easy to react with polyurethane, acrylic acid and other organic materials.