Effect Of New Viscosity Stabilizer MT On The Properties And Vulcanization Kinetics Of Natural Rubber

2-Mercaptobenzothiazole (MT) as a new type of viscosity stabilizer was adopted to prepare constant viscosity natural rubber (CVNR) and compared with the conventional one, hydroxylamine hydrochloride(HH). The effects of the dosage and types of viscosity stabilizer on the physics-chemistry properties were studied. The performance of the vulcanizates of CVNR prepared with different viscosity stabilizer was discussed.And the curing kinetics coefficient were analyzed by vulcametnizer.In terms of physics-chemistry properties, the effects of the dosage and types of viscosity stabilizer on the physics-chemistry properties, the increase value in plasticity (AP) and Mooney viscosity (△Mv) after accelerated storage hardening of natural rubber (NR) were investigated, also with the variation of weight average molecular weight (Mw), Po, and My during the accelerated storage.Thermogravimetry analysis(TG) and differential thermal analysis(DTA) were utilized to study thermal degradation of MT wsa discussed.The results show that HH and MT respectively the NR prepared has good viscosity-maintaining effect (△P≤1,△MV<4). During accelerated storage, Mw,-P0and Mv of MT-CVNR are basically constant, but these of HH-CVNR increased at longer storage time and gradually lost the viscosity-stabilizing effect. The results of TG and DTA show that,thermal degradation of both of the CVNR in nitrogen are an one-step reaction. To and Tp of HH-CVNR are lower than those of MT-CVNR.Which indicate that the thermal stability of MT-CVNR is better than that of HH-CVNR.In terms of the vulcanizates performance, the different of viscosity stabilizer were utilized to study the vulcanization characteristics and vulcanizates performance of NR was discussed.The results of vulcanization characteristics show that,t10and t90of MT-CVNR are obviously lower than those of HH-CVNR,while the maximum torque(MH) is higher than that of HH-CVNR. The tensile strength of MT-CVNR is24.0Mpa,and the teraind strength is32.7KN/m.It is obviously higher than those of HH-CVNR.In terms of the vulcanization kinetics, the results showed that the reaction degree of samples maturated in different time all was near1.The MT and HH didn’t affect vulcanization process,but it affected vulcanization velocity.The kinetics constant increased obviously along with the temperrature coefficient of vulcanization extending.The adding of HH decreased kinetics constant,which showed that HH restrained the activity of microorgan in NR latex.In this study,a new type of viscosity stabilizer was adopted to prepare CVNR. It provided theory support for exploring new type of high properties of CVNR and developing more suitable and non-toxic viscosity stabilizer.