Comparative study among TMTD, TBzTD, and ZBEC accelerators in isobutylene‐isoprene elastomer vulcanization

Abstract

Accelerators such as tetramethylthiuram disulfide (TMTD) are responsible for releasing nitrosamines, considered carcinogenic by international organizations. Tetrabenzylthiuram disulfide (TBzTD) and zinc dibenzyldithiocarbamate (ZBEC) are indicated as substituents of TMTD for not releasing noxious nitrosamines. Thus, the objective of this work was to compare the use of TMTD, TBzTD, and ZBEC accelerators in the production of isobutylene-isoprene rubber compounds. It was evaluated the effect of TBzTD/mercaptobenzothiazole and ZBEC/ N-cyclohexyl-2-benzothiazolesulfenamide pairs in the rheological properties and the first pair achieved better results. Subsequently, it was evaluated compounds containing TBzTD and ZBEC accelerators separately. The experimental design data of the obtained maximum torque were correlated by an interpolation method (thin-plate spline interpolation method). Physical-mechanical and thermodynamic measurements showed a decrease in the mechanical properties of TBzTD and ZBEC compounds. Thermogravimetric analysis did not indicate thermal differences between the compounds, Fourier transform infrared and swelling degree analyses corroborated the difference found in the crosslink densities of the compounds.

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

“…The most beneficial influence on the vulcanization and performance of NR/CSM blends had tetramethylthiuram disulfide (TMTD), whereas the lowest activity was determined for 2-mercaptobenzothiazole (MBT). The highest activity of TMTD was also reported by Gobbi et al [11] for sulfur vulcanization of isobutylene-isoprene rubber compounds. It should be noticed that TMTD is both an accelerator and a sulfur donor, which may increase the content of sulfur in the curing system and consequently the crosslink density of the vulcanizates.…”

“…The influence of the curing system composition, i.e., the sulfur/accelerator ratio and the type of accelerator used, has been extensively studied for various rubbers [7][8][9][10][11][12]. For example, Formela et al [10] applied different accelerators to vulcanize reclaimed rubber.…”

Leather-like composite materials prepared from natural rubber and two leather wastes: Wet blue leather and finished leather

“…Moreover, tetrabenzylthiuram disulfide (TBzTD) was used as a non-carcinogenic accelerator in the sulfur vulcanizing system to reduce the generation of hazardous nitrosamines in rubber compounds. 26,27 Finally, the cure characteristics, functional groups analysis, tensile properties, hardness, thermal aging, thermal stability, morphology and chromium detection of the as-prepared composites were comparatively investigated.…”

The Influence of Curing Systems on the Cure Characteristics and Physical Properties of Styrene–Butadiene Elastomer

“…The highest maximum torque during the rheometric measurements, as well as the highest hardness and modulus at 100% and 300% relative elongations, were achieved for the elastomers cured with TMTD. This was due to the highest crosslink density of the TMTD-containing vulcanizates, since TMTD acts as a sulfur donor, increasing the content of sulfur in the curing system [ 11 ].…”

“…However, the performance of Activ8 was studied in combination with only sulfenamide accelerators, so not with MBT and DPG. As it is known from the literature reports [9][10][11][12], depending on the type of vulcanization accelerators used at the same time, their interaction may be different and the synergistic effect leading to the improvement of curing characteristics of rubber compounds and the performance of vulcanizates is not always observed. Therefore, it seems reasonable to evaluate the effect of Activ8 in combination with the accelerators of different characteristics than sulfenamides, i.e., from the group of thiazoles and guanidines.…”