There are significant differences between methyl silicone rubber (dimethyl silicone rubber) and methyl vinyl silicone rubber (MVQ) in molecular structure, vulcanization properties, application areas and process characteristics. The specific analysis is as follows：


1. Molecular structure differences
Methyl silicone rubber: The main chain is composed of a silicon-oxygen bond (Si-O), and the side chain contains only a methyl group (-CH₃). The molecular structure is regular and the crystallinity is high.
Methyl vinyl silicone rubber: On the basis of methyl silicone rubber, a small amount of vinyl groups (-CH=CH₂) are introduced into the side chain, and the vinyl content is usually 0.1%~0.3% (molar fraction).The introduction of vinyl destroys the regularity of the molecular chain and reduces the crystallinity.
2. Comparison of vulcanization properties
Methyl silicone rubber: low vulcanization activity, requires high temperature (usually>150℃) and a long vulcanization time, and requires the use of highly active organic peroxide vulcanizing agent.During the vulcanization process, it is easy to cause incomplete vulcanization of thick products due to insufficient heating of the inner layer, resulting in air bubbles.
Methyl vinyl silicone rubber: The introduction of vinyl has significantly improved the vulcanization activity, supported more types of peroxide vulcanizing agents, and reduced the amount of vulcanizing agents.The vulcanization efficiency is high, the thick products are evenly vulcanized, and the compression and permanent deformation resistance is excellent (better support at high temperatures).
3. Differentiation of application areas
Methyl silicone rubber: Due to the difficulty of vulcanization and high temperature compression deformation, it has gradually been replaced by methyl vinyl silicone rubber. It is now mainly used in scenes with low performance requirements, such as simple seals and insulating materials.
Methyl vinyl silicone rubber: With its excellent high and low temperature resistance (-55℃~300℃), compression deformation resistance and process performance, it has become the mainstream product of silicone rubber.Widely used in：
Sealing field: O-ring, oil seal, pipe seal gasket；
Medical field: medical catheters, artificial organs；
Industrial field: rubber rollers, sealants, adhesives；
Composite material: silicone masterbatch base glue, mixed with gas phase silica and other compounding agents.
4. Differences in process characteristics
Methyl silicone rubber: Raw rubber is a colorless and transparent elastomer, but the vulcanization process is complex, the processing of thick products is difficult, and the yield is low.
Methyl vinyl silicone rubber: excellent process performance, can be made into thick products, pressed out and rolled semi-finished products with smooth surface, easy operation and high production efficiency.