Study On The Characteristics Of Curing CM Via DMTD And Its Derivates

Chlorinated polyethylene (CM) is a kind of special rubber with excellent properties, such as ozone resistance, weather resistance, impact resistance, oil resistance, chemical resistance and flame resistance. The research of new curing system is an important part of the basic research of CM rubber application. To this end, to carry out the synthesis of derivatives of 2,5-dimercapto-1,3,4-thiadiazole and the application of basic research in CM crosslink, can enrich the CM curing system, expand the scope of application of CM in the rubber industry to provide a theoretical basis. The main contents of this paper include:1.5-mercapto-2-monobenzoate thioestet-1,3,4-thiadiazole (TDD) was used to cure chlorinated polyethylene elastomer (CM). Curing kinetics of TDD/CM system was studied via an oscillating disk rheometer at different temperatures (150～180 ℃). Based on the curing curves and vulcanization characteristic parameters, the kinetic characteristic of TDD/CM system in heat curing period and flat curing period were studied. The results showed that, the apparent reaction order n of TDD/CM system in heat curing period and flat curing period of were 1.03～1.19 and 0.33～0.55, and the apparent reaction activation energy was 33.3kJ/mol and 50.6kJ/mol respectively.2. Different formulations were prepared by changing the amount of curing agent, choosing different accelerator and acid binding agent by changing the amount of curing agent, using 2- -5-methyl-1,3,4-(TDD) as curing agent. The curing curves of different curing systems and the mechanical properties of vulcanized rubber were determined. The results showed that with the increase of the amount of curing agent, the mechanical properties of the curing agent was better, and the promoting effect of accelerator 808 on TDD/CM vulcanization system was better, and the binding acid effect of MgO was the best.3.2,5-dimercapto-1,3,4-thiadiazole (DMTD) was used as the precursor, and its two derivates,2-mercapto-5-benzoyl-1,3,4-thiadiazole (TDD) and 2-mercapto-5-benzenesulfonyl-1-1,3,4-thiadiazole (MBSTD) were synthesized, and their chemical structures were confirmed by FTIR and DSC. After that, the curing curves and characteristic parameters of CM cured by DMTD, TDD and MBSTD were recorded via a Monsanto type cure-meter. Finally, the crosslink kinetics of CM cured by DMTD, TDD and MBSTD were studied. The results suggested that, when CM was cured by the three curing agents, the curing reactions were of the characteristic of autocatalytic reactions, and they all conformed to Sestak-Breggren model. Besides, after DMTD was converted into TDD or MBSTD, the curing reaction was accelerated and Ea decreased. The Ea of CM cured by DMTD, MBSTD and TDD were 100.2kJ/mol,80.9kJ/mol and 63.5 kJ/mol respectively.