The difference between double two four and double two five vulcanizing agents:
Double two four:
The advantages of bis (2,4) are low decomposition temperature and fast decomposition speed, so it is a commonly used curing agent for extrusion molding compound. However, because the decomposition temperature is too low, the scorching performance is poor, so the amount should be as little as possible. The decomposition products are 2,4-dichlorobenzoic acid and 2,4-dichlorobenzene, which are toxic and affect the heat resistance of the rubber mixture products. Because carbon black affects the vulcanization of bis (diethylene glycol), it cannot be used for the compound containing carbon black.
Double two five:
The double two five decomposition temperature is high, and the scorching performance is good. As no product with carboxyl group is produced during decomposition, the thermal stability of the rubber mixture is not affected. Double 25 can be used for the compound containing carbon black, with a wide range of applications. When double 25 is used for vulcanization, the compression deformation of the vulcanizate is low, and the elongation is high.
In addition, when the amount of peroxide exceeds the appropriate amount, the elongation and tear resistance of the vulcanizate will be reduced, and the effect of double bis (IV) will be greater.
Double two four is generally used for extrusion, and double two five is used for molding.
Double two four is generally used in extrusion calendering process, and the curing temperature is generally 120 β. Double two five is generally used in molding, and the curing temperature is 170 β. Another difference is that double two five is a special vinyl curing agent. Double two four is universal.
For silicone rubber, please check the details:
https://www.htvsilicone.com/product-silicone-gum-for-hcr-manufacturing-iotagum709.html
