Bis-2-tetra vulcanizing agent will produce toxic gases during the vulcanization process, but it is not very serious.

Bis-25 vulcanizing agent and bis-2-4 vulcanizing agent are the two most important silicone rubber vulcanizing agents. They have both differences and similarities.

Bis-25 vulcanizing agent has a high decomposition temperature and good scorch performance. Since no products with carboxyl groups are produced during decomposition, it does not affect the thermal stability of the mixed rubber. Bis-25 vulcanizing agent can be used in rubber compounds containing carbon black and has a wide range of applications. When bis-25 vulcanizing agent is used, the vulcanized rubber has lower compression deformation and higher elongation: at the same time, bis-25 vulcanizing agent is a vinyl-specific vulcanizing agent.

The advantages of ditetrafluoroethylene vulcanizing agent are low decomposition temperature and fast decomposition speed, so it is a commonly used vulcanizing agent for extrusion molding compound rubber. However, due to the low decomposition temperature of bis-2-tetrasulfide, the scorch performance is not good, so the dosage should be as small as possible. The decomposition products are 2.4-dichlorobenzoic acid and 2.4-dichlorobenzene, which are toxic and affect the heat resistance of the mixed rubber products. Because carbon black interferes with the vulcanization effect of the bis-2-tetra vulcanizing agent, it cannot be used in compounds containing carbon black: the bis-bis-tetra vulcanizing agent can be used as a general-purpose vulcanizing agent.

In addition, when the amount of peroxide exceeds the appropriate amount, the elongation and tear strength of the vulcanized rubber will decrease, and the double 24 will have a greater impact. Double 24 is generally used for extrusion, and double 25 is used for molding. Double 24 is generally used in the extrusion calendering process, and the vulcanization temperature is generally 120°C. Double 25 is generally used in molding, and the vulcanization temperature is 170°C. Another difference is that Shuang25 is a special vulcanizing agent for vinyl. Double 24 is a universal type

Below we will briefly popularize platinum silicone products and double 24 silicone products from three aspects, hoping to help everyone identify when purchasing such products:

1. Transparency

Under normal circumstances, platinum silicone products use gas-phase silica gel with good transparency or particularly high transparency as the base glue, and the products produced have very good transparency; while for double-24 silicone products, most of them use sinking silica gel as the raw material, and the products are semi-silica gel. transparent.

2. Smell

Silicone products vulcanized with platinum basically have no residual odor on the products, are odorless and non-toxic, and reach the EU food grade level; while silicone products vulcanized with bis-2-tetrafluoroethylene will leave a strong irritating odor, which will evaporate after long-term exposure. It will still exist, and it is easy to distinguish the smell difference between the two.

3. Store to see if the surface evaporates.

Under normal circumstances, silicone products obtained by platinum vulcanization will not form frost on the surface after being stored for a period of time; however, the frost will be quite serious on the surface of silicone products vulcanized by bis-2-2-tetrafluoroethylene. Of course, some manufacturers will also respond to customer requirements before production and shipment. Secondary vulcanization is added to the process to reduce the occurrence of frost in the later stage. It can be said that if a silicone product with a large amount of frost on the surface is stored for a period of time, it must be an ordinary silicone product vulcanized with bis-2-tetra.