The Effect of Vulcanization Accelerator on the Properties of Porous Rubber

This work is devoted to identifying the patterns of influence of the vulcanization accelerator N-cyclohexyl-benzothiazyl-sulfenamide (CBS) on the technological, physico-mechanical, and thermo-physical properties of vulcanizates based on styrene-butadiene rubber. It was found that a decrease in the content of the vulcanization accelerator decreases the maximum torque, and a noticeably longer time is required for optimum vulcanization in the absence of CBS. The thermal conductivity in vulcanizates increases with a decrease in the accelerator concentration due to changes in the structure and molecular mobility of kinetic units. Physico-mechanical indicators increase with a decrease in the concentration of CBS, this is due to a decrease in the apparent density of porous rubbers

Xanthate-modified nanoTiO2 as a novel vulcanization accelerator enhancing mechanical and antibacterial properties of natural rubber

With the emerging of sustainability, the fabrication of effective and eco-friendly agents for rubber industry has attracted extensive attention. In this study, a novel and nontoxic titanium dioxide-based vulcanization accelerator (xanthate-modified nanotitanium dioxide (TDSX)) with excellent antibacterial performance, for the first time, was synthesized under the catalyst of ceric ammonium nitrate. Notably, the thermal stability of xanthate was greatly enhanced after being grafted on titanium dioxide (TiO2) nanoparticles, in which the activation energy was increased from 6.4 to 92.5 kJ/mol, enabling the obtained TDSX with multiple functions, mainly consisting of fabulous vulcanization-promoting effects, reinforcing effects, antibacterial properties, and anti-ultraviolet aging effects for natural rubber (NR). Simultaneously, the TDSX can be effectively and uniformly dispersed in the rubber matrix along with the developed interface interaction between TDSX particles and rubber matrix. Compared to the traditional accelerators 2-mercaptobenzothiazole (M) system, the tensile strength and the tearing strength of NR/TDSX was improved by 26.3 and 40.4%, respectively. Potentially, our work for preparing green vulcanization accelerator can provide a new design strategy for multifunctional high performance elastomer materials.

FUNCTIONALIZED SILICA AS AN ECO-FRIENDLY VULCANIZATION ACCELERATOR TO ENHANCE THE INTERFACIAL INTERACTION IN NR/SILICA COMPOSITES

ABSTRACT Xanthate is a class of non-toxic, rapid, and eco-friendly rubber vulcanization accelerator, but it is seldom used in the rubber industry because of its poor thermostability and ease of decomposition. To overcome these drawbacks, silica supported sodium isobutyl xanthate (silica-s-SIBX) was prepared by chemically bonding SIBX onto the silica surface. After loading, the initial degradation temperature (T0), maximum degradation temperature (Tp), and final decomposition temperature (Tf) of silica-s-SIBX were increased by 85.8, 118.9, and 146.9 °C, respectively. Meanwhile, silica-s-SIBX could not only improve the dispersion of fillers in the rubber but also enhance the interfacial interaction between silica and the rubber matrix. Therefore, it may offer new scientific and technological opportunities for preparation of green additives in the rubber industry.

Optimization of Accelerator Mixing Ratio for EPDM Rubber Grommet to Improve Mountability Using Mixture Design

A grommet, made of ethylene propylene diene methylene (EPDM) rubber, is an integral part used for fixing and protecting the wire inserted from the outside to the inside of vehicles. Rubber compounds exhibit various mechanical properties and vulcanization characteristics depending on the accelerator mixing ratio. These mechanical properties affect the insertion and detachment forces when the grommet is manufactured and fixed to the vehicle body. In this study, we experimentally analyzed the changes in the properties of EPDM rubber depending on the vulcanization accelerator to improve the mounting performance of the grommet, and subsequently derived the optimum accelerator mixing ratio. We implemented a mixture design strategy to derive the optimum mixing ratio for obtaining the desired mechanical properties and vulcanization characteristics. The insertion and separation forces of the existing grommet were compared with those of the grommet fabricated using the derived mixing ratio and we found that the mounting performance was improved compared to the existing grommet.

Processes for synthesis of altax

Literature analysis was focused on the existing processes for synthesis of altax (2,2’-dibenzothiazolyldisulfide) as an important rubber vulcanization accelerator. Oxidation of mercaptobenzothiazole (captax) with various oxidants such as oxygen in the presence of catalysts, hydrogen peroxide etc., as well as electrochemical oxidation was shown to be the primary way to altax. The data from literature were the basis to develop a low-tonnage technology for synthesis of altax; the technology was developed at the Boreskov Institute of Catalysis and tested using a pilot setup at the Volgograd Department of BIC.

Branched polystyrenes from suspension “Strathclyde” polymerization using a vulcanization accelerator as a chain transfer agent

Branched polymers exhibit a unique three-dimensional (3D) molecular architecture and distinctive physical/chemical properties, and thus have been applied in a wide variety of fields.