Polydimethyl methyl vinyl siloxane, commonly known as methyl vinyl silicone rubber.The following xiaobian is about the heat resistance modification and application of methyl vinyl silicone rubber to understand it.

  Silicon rubber has good mechanical properties at high temperature and is suitable for mold manufacturing. It can be used for precision casting and low melting point metal alloy casting.

  From silicon rubber compatibility with heat resistant additives, with potassium hydroxide catalyzed ring three siloxane ring opening polymerization of poly (organic silicon potassium alcohol, methyl sealing side dimethyl polysiloxane, cerium chloride as raw materials for synthetic has good compatibility with silicone containing cerium polysiloxane (POSC), infrared spectrum and silicon - nuclear magnetic resonance (NMR) system to unravel the structure containing cerium polysiloxane.

  The thermal degradation behavior of silicone rubber was studied and the apparent activation energy of thermal degradation was calculated.The results showed that the apparent activation energy of thermal degradation of silicone rubber with POSC was 125.5 kJ/mol, which was higher than that of blank silicone rubber (51.0 kJ/mol), indicating that POSC improved the thermal stability of silicone rubber.

  Methyl phenyl vinyl silicone rubber referred to as phenyl silicone rubber.This kind of rubber is in the molecular chain of vinyl silicone rubber, the introduction of diphenyl silicon oxygen chain or methyl phenyl silicon oxygen chain.

  According to the different content of phenyl in silicone rubber (phenyl: silicon atom), it can be divided into low phenyl, medium phenyl and high phenyl silicone rubber.When the rubber crystallizes or approaches the vitrification transition point, or the two overlap, the rubber becomes rigid.The introduction of an appropriate amount of large-volume groups destroys the regularity of the polymer chain, thus reducing the crystallization temperature of the polymer. Meanwhile, the introduction of large-volume groups changes the intermolecular forces of the polymer, so the glass transition temperature can also be changed.   

  Low phenyl silicone rubber (C6H5/Si=6~11%) has excellent low temperature resistance due to the above reasons, and has nothing to do with the type of phenyl monomer used.The brittleness temperature of vulcanized rubber is -120℃, and it is a good rubber with low temperature performance.Low phenyl silicone rubber has the advantages of vinyl silicone rubber, and the cost is not very high, so there is a trend to replace vinyl silicone rubber.When the content of phenyl is greatly increased, the rigidity of molecular chain will increase, resulting in the reduction of cold resistance and elasticity, but the ablative and radiation resistance will be improved, the phenyl content of C6H5/Si=20~34% medium phenyl silicone rubber has the characteristics of ablative resistance. High phenyl silicone rubber (C6H5/Si=35~50%) has excellent radiation resistance.