Study on sulfur vulcanized natural rubber formulated with nitrosamine safe diisopropyl xanthogen polysulfide/tertiary butyl benzothiazole sulphenamide binary accelerator system

Abstract

An outstanding interest on elimination of nitrosamine generation in traditional sulfur vulcanization systems has led to introduce nitrosamine safe accelerator/s to produce safe natural rubber (NR) vulcanizates. It is an effective way to prevent formation of carcinogenic N-nitroso compounds during manufacture of rubber products. In the present study, behavior of nitrosamine safe binary accelerator system consisting of diisopropyl xanthogen polysulfide (DIXP) with commonly used non-regulated accelerator N-tert-butyl-2-benzothiazole sulfenamide (TBBS) was investigated in efficient sulfur vulcanization of NR. Cure characteristics, physico-mechanical properties and crosslink density of vulcanizates prepared with different combinations of the accelerator system were evaluated and compared with those of individual accelerators. The study reveals that moduli and strength properties of the vulcanizate prepared with DIXP accelerator are inferior to those of the vulcanizate prepared with TBBS accelerator. Nevertheless, optimum cure time of the DIXP compounds is lower in comparison to TBBS compounds. Moreover, progressive replacement of DIXP with TBBS in the accelerator system showed a synergistic effect in regard to cure characteristics and physico-mechanical properties.

The Synergistic Effect of Dibenzyldithiocarbamate Based Accelerator on the Vulcanization and Performance of the Silica-Filled Styrene–Butadiene Elastomer

“…Two or more accelerators can be used together to accelerate the vulcanization by providing a synergistic effect on curing. Appropriate selection of these accelerators allows for better control of the vulcanization process and for the obtention of a good balance between safe processing and quick vulcanization of rubber compounds [13][14][15][16][17]. Ahsan et al [18] reported the synergistic effect of mercaptobenzothiazole disulfide (MBTS), zinc 2-merkaptothiazole (ZMBT) and 1,3-diphenylguanidine (DPG) in sulfur vulcanization of NR compounds.…”

Synergistic combination of 2-mercaptobenzothiazole (MBT) and nitrosoamine-safe thiuram disulfide as advanced rubber vulcanizing accelerators

“…Different preventive measures have been taken to reduce toxicity, [17][18][19][20][21][22][23][24][25][26][27][28][29] but using nitrosamine-safe accelerators [22][23][24][25][26][27][28][29] was the most important from a technological point of view. The term "safe-amine" is used for the amine which does not form carcinogenic nitrosamines on nitrosation.…”

The use of diisopropyl xanthogen polysulfide as a potential accelerator in efficient sulfur vulcanization of natural rubber compounds

“…In one of our previous studies, nitrosamine safe DIXP/tertiary butyl benzothiazole sulphenamide (TBBS) binary accelerator system showed a synergistic effect regarding cure characteristics and physicomechanical properties of sulfur vulcanized NR compounds. 27 Although DIXP does not contribute to generating harmful nitrosamines, its performance as a single accelerator does not provide adequate moduli and strength properties in comparison to the TBBS accelerator. This study aims to evaluate the synergistic effect of binary accelerator systems of DIXP/TBzTD and DIXP/ZBeC on cure characteristics, physicomechanical, aging, dynamic mechanical, and thermal properties of NR vulcanizates prepared with an efficient sulfur vulcanization system, in view of introducing a novel binary accelerator system/s to formulate nitrosamine safe vulcanizates from NR.…”