Curing accelerator refers to a complexing agent that can speed up the curing reaction, shorten the curing time, reduce the curing reaction temperature, and reduce the amount of curing agent, referred to as accelerator. The discovery and application of accelerators, especially organic accelerators, have played an important role in the development and progress of the rubber industry. Before the appearance of organic additives, the vulcanization time is up to several hours, and the sulfur content is 7-9 parts.
After using accelerators, the vulcanization time can be reduced to a few minutes to tens of minutes. Due to the shortening of vulcanization time and the reduction of vulcanization temperature, the cost is reduced, and the damage to rubber caused by high temperature oxidation is also reduced. The application of accelerators can reduce the number of sulfur atoms in polyphobic cross-linking bonds and the structure of cyclized rubber polymers. On the one hand, it can improve the heat resistance and other properties of the product, and on the other hand, it can reduce the amount of hydrophobic yellow, thereby reducing the The phenomenon of "sulfur spraying" of the rubber material shows that the use of accelerators has great technical and economic effects, so accelerators are one of the essential basic raw materials in the rubber industry.
Thiurams used in vulcanization accelerators, including thiuram monosulfide, thiuram disulfide and thiuram polysulfide, are the general structural formula of thiuram derivatives, including thiuram disulfide and polysulfide Thiuram can be used as a curing agent because it releases active sulfur or sulfur radicals at standard vulcanization temperatures. Commonly used products are: TMTD, TMTM, DPTT, TBzTD, TETD. During the vulcanization process, various properties will change with the vulcanization process. The change curve can reflect the vulcanization process of rubber. At a certain curing temperature, the torque of the rotor varies with the curing time.