Vinyl silicone oil and methyl vinyl silicone rubber (raw rubber) tend to turn yellow after being stored for a period of time. This is due to the high temperature oxidation of vinyl in the air. In addition, the raw material D4 or DMC is not pure, and many impurities will also turn yellow. , and share some solutions to solve the yellowing of vinyl silicone oil and raw rubber.

1. The reaction temperature should not be too high, and the general batch production should not exceed 160 degrees.

2. The vacuum degree of the reactor must be good, not to mention the absolute pressure of at least 99%, and nitrogen protection.

3. The quality of vinyl end capping agent or ring body is better, and Cl ion and impurity end capping agent must be controlled below dozens of ppm.

Moisture content is related to polymerization, but does not affect yellowing. H2O is equivalent to end-capping agent, and at most 107 glue is mixed in the product. The lower the viscosity or the higher the vinyl content, the easier it is to yellow. By doing the above three points, the general yellowing problem can be controlled. In addition, antioxidants can be added to increase the anti-yellowing effect.