Natural latex collected from rubber trees cannot be used directly, but must be supplemented with latex additives, such as antioxidants, accelerators and vulcanizing agents. Accelerators are one of the main varieties of rubber additives and have the largest number of classifications.

A. What is an accelerator? What is the function?
Promoter is also called vulcanization accelerator, or promoter. Where the vulcanizing agent activation, accelerate the vulcanizing agent and rubber molecules between the cross-linking reaction, so as to shorten the vulcanization time and reduce the vulcanization temperature of the substance called vulcanization accelerator.

The main role of accelerator has the following five: (1) accelerate the speed of vulcanization; (2) shorten the vulcanization time; (3) reduce the vulcanization reaction temperature; (4) reduce the amount of vulcanizing agent; (5) improve the physical and mechanical properties of vulcanized rubber.

Second, the classification and selection of accelerators
As there are many types of accelerators on the market, there are also many classifications, which can be classified from different angles. Here we introduce 4 common ways of classifying accelerators.

(A) by chemical structure classification

1、Thiazole (sāi zuò) class: Representative products M, DM, MZ.

2, hyposulfamide (xiān àn) class: representative products TBBS, CZ, DZ, NOBS, NS.

3、Thiuram class: representative products TMTD, TMTM, TETD, DPTT, etc.

4, dithiocarbamates: representative products ZBEC, ZDC, BZ, PZ.

5、Xanthates: representative products DIP, ZIX. these accelerators are mainly used in the vulcanization of room temperature latex because of their fast promotion speed, and compared with the vulcanizing agent of Tyuram class, also has the advantage of not producing carcinogenic substances such as nitrosamines.

In addition to the five types, there are guanidine (guā) category: representative products DPG, DOTG; thiourea (liú niào) category: representative products ETU, DETU, DPTU; aldehyde amine (quán àn) category: representative products H, 808, and so on.

(B) classification according to pH value
1、Acidic (type A): thiazole class, thiram class, dithiocarbamate class xanthate class.
2, alkaline (B type): hyposulfamide class, thiourea class.
3、Neutral accelerator (N type): guanidine, aldehyde amine class.

(C) classification according to the speed of vulcanization promotion
1、Slow-speed grade: thiourea, aldehyde amine class, representative products ETU, DETU, H
2、Medium speed: guanidine, representative products DPG, DOTG
3、Quasi-speed class: thiazole, hypoxanthamide class M, DM, CZ, DZ, NOBS
4、Ultra-rapid grade: Tyuram class, representative products TMTD, TMTM, TETD
5, super speed grade: dithiocarbamates, xanthates, representative products PZ, ZDC, BZ

(D) according to the amount of market consumption or production to classify
The consumption or production is called large varieties, and the opposite is called small varieties.
1、Large varieties: thiazoles and hyposulfamates.
2、Small varieties: Tyuram, dithiocarbamates, thioureas, xanthates.