Dimethyl silicone oil has many outstanding properties, so it is widely used in various sectors of industrial and agricultural production, defense industry, scientific research and medical and health sectors. Dimethyl silicone oil is divided into: high temperature vulcanization silicone and room temperature vulcanization type. What should I do if dimethyl silicone oil turns yellow after high-temperature vulcanization?

High-temperature vulcanized silicone dimethicone usually requires secondary vulcanization to eliminate decomposed residues in the oxide and further cross-link the silicone rubber to achieve optimal physical properties. Second-stage vulcanization causes dimethyl silicone rubber to turn yellow and reduce transparency, which directly affects the appearance of the product. Its application scope is limited to industries such as food, medical and solar photovoltaics.

There are different reasons for the yellowing of dimethicone. Some think it is caused by trace metal elements and NO-3 contained in the raw materials and additives for producing dimethyl silicone; some think it is caused by the decomposition of dialkyl peroxide. The production of acetone leads to the condensation and dehydration of α-hydroxybutyraldehyde, resulting in the formation of conjugated compounds; some also believe that the pH value of silica affects the yellowing of silicone rubber. However, the current solution to the yellowing of dimethyl silicone oil mainly focuses on the three aspects of raw rubber, silica and additives.

The following are several ways to improve the yellowing of silicone rubber:

1. Add an anti-yellowing paste bis-2,5 vulcanizing agent containing a high amount of hydrogen silicone oil to significantly improve the anti-yellowing effect of silicone rubber, increase the transparency of dimethyl silicone oil, and prevent the vulcanizing agent from splashing.

2. Organic surfactant is added to white carbon black to control the size of secondary particles. Under the action of compound anti-yellowing agent, it can effectively control the yellowing degree of dimethyl silicone oil.

3. Add an anti-yellowing agent called pyrophosphoric acid to enhance the anti-yellowing ability of the mixed rubber without reducing the physical and mechanical properties of the mixed rubber.

Dimethicone should be stored in a ventilated, dry warehouse to prevent direct sunlight and isolate fire sources. Dimethicone will not be absorbed by the digestive system, has no irritation to the skin, and has slight irritation to the cornea, but no harm. No protective measures are required during operation. You can use the above methods to solve the problem of yellowing of dimethyl silicone oil.


Regarding silicone oil, please view details:
https://www.siliconefoam.net/product-hydroxyl-blocking-polymethyl-silicone-oil-(general-type)-iota-1203-.html