Both nitrile rubber and nitrile reclaimed rubber have excellent oil resistance and wear resistance, so they are widely used in oil resistant rubber products and wear parts; although the heat resistance of nitrile rubber/recycled rubber is higher than natural rubber and butyl Benzene rubber and butadiene rubber, but there is still a certain gap with high temperature EPDM rubber; in actual production, nitrile rubber products often need to work in high temperature oil medium, then increase the heat resistance of nitrile vulcanizate Sex? The vulcanization system is one aspect that rubber product manufacturers must consider. 1JLYY731.
There are three kinds of vulcanization systems commonly used in nitrile rubber: sulfur vulcanization, peroxide vulcanization and resin vulcanization. The vulcanization properties of vulcanized rubbers are different.
1. Characteristics of nitrile vulcanizate after vulcanization of three vulcanization systems
(1) Sulfur vulcanization system: Sulfur is the most traditional vulcanizing agent. When vulcanized nitrile rubber is vulcanized, the less sulfur is used, the better the heat resistance of vulcanized rubber. Therefore, rubber manufacturers who have heat resistance are more willing to The low sulfur blending is selected, and the amount of the vulcanization accelerator is appropriately increased to improve the heat resistance of the vulcanizate while improving the vulcanization effect.
(2) Peroxide curing system: The use of peroxide-vulcanized nitrile rubber will produce excellent carbon-oxygen bonds during crosslinking, and the vulcanized rubber not only has good thermal stability, but also It can improve the oil resistance of the rubber and reduce the shrinkage of the rubber to a certain extent.
(3) Resin vulcanization system: Phenolic resin is the most common vulcanizing agent in resin vulcanization system. The most obvious feature is high temperature resistance. Therefore, the use of phenolic resin as vulcanizing agent can impart excellent heat aging resistance to nitrile vulcanizate. The rubber products that come out can maintain good performance for a long time at a high temperature. Therefore, many manufacturers of nitrile rubber products use phenolic resins in their formulations, especially heat-resistant nitrile rubber products.
2. How to choose a suitable heat-resistant nitrile product vulcanization system
Compared with the sulfur vulcanization system with low sulfur content, it is obvious that the vulcanized rubber after peroxide vulcanization and the rubber vulcanized rubber have better heat resistance. However, in actual production, the peroxide vulcanization process is very restrictive and the vulcanization cost is too high, so Xiaobian does not recommend this vulcanization system. In contrast, resin vulcanization systems are more common, but the vulcanization rate is slower during vulcanization, the production cycle is longer, and the cost is invisibly increased. Therefore, Xiaobian recommends that you choose a sulfur-sulfur system with low sulfur content, increase the amount of vulcanization accelerator, increase the vulcanization effect and heat resistance of the nitrile vulcanizate, or use a resin vulcanization system and a low sulfur compounding system.
Nitrile rubber and nitrile reclaimed rubber are commonly used materials for the production of oil-resistant and wear-resistant rubber products. The nitrile reclaimed rubber can replace the nitrile rubber to reduce the cost of the product; but the molecular structure and properties of the nitrile reclaimed rubber and nitrile rubber There are certain differences. Therefore, when designing the nitrile rubber and nitrile reclaimed rubber and using the vulcanization system of the rubber, the rubber product manufacturer must combine the characteristics of the two to reasonably adjust the type and amount of the vulcanizing agent and the accelerator in the vulcanization system.