What are the combined analysis of rubber accelerators?

What are the analysis of rubber accelerators and combinations?

When selecting accelerators from the aspects of process performance and product performance, the single use of accelerators often cannot receive ideal results. For example, although the accelerator DPG can confer high tensile strength and tensile stress on vulcanized rubber, it has slow sulfur velocity, poor flatness, and poor heat aging resistance of vulcanized rubber; Although the accelerator TMTD has fast sulfur speed and high vulcanization degree, its processing safety is poor, and it is easy to scorch and persulfurize; Thiazole and sulfonamide vulcanized rubber has high tensile strength and good wear resistance, heat resistance, aging resistance, vulcanization flatness is also good. In order to further improve the vulcanization speed and achieve high use value, 2-3 accelerators are often used in the design of the vulcanization system in the rubber formula to receive the effect of complementing each other or activating each other, so as to adapt to the needs of processing technology and improving product quality.

Rubber accelerator and collocation analysis

When promoters are used together, one type of promoter is usually used as the main promoter (called the main promoter or the first promoter) and the other is used as the secondary promoter (called the secondary promoter or the second promoter). The amount of primary accelerator is larger, and the amount of secondary accelerator is smaller (generally about 10% ~ 40% of the amount of primary accelerator).

Combined classification

1. Accelerators are divided into three categories according to acid and alkali. One is the acid accelerator (with the letter A to represent) : including thiazole, thiuram, dithiocarbamate, xanthate; The second is alkaline accelerators (denoted by the letter B) : including guanidine and aldehyde-amine; Third, neutral accelerators (denoted by the letter N) : including secondary sulfonamides and thioureas. Promoters are classified into AB, AA, BB, NA, NB, NN, etc., according to the combination of acid and base, but the common use is the combination of acid and base (AB), acid and acid (AA), medium acid (NA).

2. Accelerators are divided into five categories according to curing speed. In the world, it is customary to compare the vulcanization rate of accelerator M with the effect of accelerator M on natural rubber. Slow grade: aldehydes, amines, thiourea; Medium speed grade: guanidine; Quasi-overspeed class: thiazole, subflavanides; Overspeed: Thiuram; Super speed class: dithiocarbamate, xanthate class.