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

Abstract

This work focused on studying the effect of dibenzyldithocarbamate vulcanization accelerator on the curing characteristics and performance of styrene–butadiene elastomer (SBR) filled with nanosized silica. A dibenzyldithocarbamate derivative was applied as an additional accelerator to enhance the efficiency and the rate of sulfur vulcanization in the presence of two other accelerators, i.e., N-cyclohexyl-2-benzothiazole sulfenamide (CBS) and/or 1,3-diphenylguanidine (DPG). Furthermore, the possibility of reducing the amount of zinc oxide (ZnO) and the elimination of CBS and DPG from elastomer compounds using dibenzyldithiocarbamate accelerator was tested. Dibenzyldithocarbamate derivative applied with other accelerators (especially CBS) effectively enhances the efficiency of SBR vulcanization by reducing the optimal vulcanization time and increasing the crosslink density of the vulcanizates despite the lower amount of ZnO. Moreover, vulcanizates with dibenzyldithocarbamate demonstrate higher tensile strength while having a smaller content of CBS or DPG compared to the reference SBR composites. Thus, the synergistic effect of dibenzydithiocarbamate derivative on the vulcanization and performance of SBR was confirmed. Furthermore, dibenzyldithocarbamate derivative enables the amount of ZnO to be reduced by 40% without harmful influence on the crosslink density and performance of the vulcanizates. Finally, it is possible to replace CBS with a dibenzyldithiocarbamate derivative without the crosslink density and tensile strength of the vulcanizates being adversely affected, while improving their resistance to thermo-oxidative aging.

The Potential Application of Starch and Walnut Shells as Biofillers for Natural Rubber (NR) Composites

“…Mechanical loss factor (tan δ) is a measure of the energy dissipated as heat by the elastomer network during each deformation cycle. By definition, tan δ is the ratio of the loss and the storage moduli (E”/E’) and corresponds to the material’s ability to dampen vibrations [ 63 , 64 ]. As expected, the highest value of tan δ at T g ( Table 5 ) was exhibited by the unfilled vulcanizate.…”

Influence of accelerators and curing system composition on the cure characteristics, crosslinks structure and properties of acrylonitrile‐butadiene elastomer

“…The lowest values of T 5% were determined for the vulcanizates containing DPG, especially in the EV system, which contained the highest amount of DPG. It was due to the lower thermal stability of DPG as compared to CBS and TMTD 10,45 . Regarding the sulfur/accelerator ratio and consequently the structure of crosslinks, no significant effect on the T 5% was observed considering the standard deviation of the obtained results.…”

“…It was due to the lower thermal stability of DPG as compared to CBS and TMTD. 10,45 Regarding the sulfur/accelerator ratio and consequently the structure of crosslinks, no significant effect on the T 5% was observed considering the standard deviation of the obtained results.…”

“…Plates of vulcanizates were stored in a drying chamber (Binder, Tuttlingen, Germany) at 100°C for 7 days (168 h). The resistance of the samples to aging was determined according to the procedure described previously 10 . The aging coefficient ( A F ), which quantifies the resistance of elastomer to thermo‐oxidation, was calculated according to Equation (), 32 where tensile strength (TS) is the tensile strength of vulcanizates, and E b is the elongation at break. …”

“…The influence of the sulfur/accelerator ratio on the vulcanization, crosslink structure and final properties of the cured material has been studied for various rubbers, that is, natural rubber, 7,8 isobutylene–isoprene rubber, 9 styrene‐butadiene rubber, 10 ethylene‐propylene‐diene terpolymer 11 or chlorosulfonated polyethylene 12 . The effect of sulfur/accelerator ratio on the structure, that is, polysulfidity, of crosslinks in the elastomer network was confirmed and correlated with the influence of crosslinks structure on the performance of vulcanizates.…”