TESPT tetrasulfide

TESPT B -(triethoxysilyl-propyl)tetrasulfide (coupling agent) Si 69 Evonik... 

The hydrophilic nature of silica also affects the cure characteristics of rubber compounds, the properties of vulcanized rubber and also the compatibility with non-polar rubber such as natural rubber (NR). Silica retards the vulcanization as it reacts with zinc-accelerator-sulfur complex. These drawbacks can be overcome through the use of silane coupling agents. The most common silane coupling agent used is bis(3-triethoxysilylpropyl) tetrasulfide (TESPT). A silane... 

Ito et al. examined the ESR spectra of surface modified silica filled SBR unvulcanizates to get information on the filler/rubber interactions. The ESR spectra of vinyl trimethoxy silane (VS) modified silica filled SBR unvulcanizates (U-VS) and (bis(triethoxysilyl propyl)-tetrasulfide (TESPT) modified silica filled SBR unvulcanizates (U-TESPT) measured at —100 °C and at dilferent initial strains are shown in Figure 25.28(a) and (b), respectively. It is found that the intensity of signals increases with increasing initial strain without changes in... 

Furthermore Li et al. reported the use of a novel method (Two-Step Method, TSM) to investigate the modification process in preparation of rubber, silica, and bis(3-triethoxysilylpropyl) tetrasulfide (TESPT). The TSM modification indicated that the TESPT hydrolyzed firstly to generate the silanol (Si-OBT), and the silanol reacted with the hydroxyl groups on the surface of siUca. The properties of modified silica were studied and results exhibited the advantages of TSM, and also revealed that 8 % TESPT amount was suitable than 12 and 15 % TESPT amount [120]. 

In recent years, lamellar nanofiUers have been established as the most important filler type for barrier and mechanical reinforcement. Dal Point et al. reported a novel nanocomposite series based on styrene-butadiene rubber (SBR latex) and alpha-zirconium phosphate (a-ZrP) lamellar nanofiUers. The use of surface modified nanofiUers improvement the mechanical properties. However, no modification of the gas barrier properties is observed. The addition of bis(triethoxysilylpropyl) tetrasulfide (TESPT) as coupUng agent in the system is discussed on the nanofiUer dispersion state and on the fiUer-matrix inteifacial bonding. Simultaneous use of modified nanofillers and TESPT coupling agent is found out with extraordinary reinforcing effects on both mechanical and gas barrier properties [123]. 

Today, for the hydrated precipitated silica to be effective in reducing the rolling resistance in a tire tread, it must be used with an organosilane. The most common organosilane used today as a rubber compounding ingredient for use with silica is TESPT (bis-[3-(triethoxysilyl)propyl] tetrasulfide). 

In here, at least one Y is hydrolyzable group, and X is a functional group such as iodine, sulfur, thiocyanate, thiourea, cyanide, etc., which is called bifunctional silane. When X is a hydrogen, it is called monofunctional silane. Two moles of 3-chloropropyltrialkoxysilanes react with one mole of disodium tetrasulphide produces bis-type bifimctional silane, which is called bis(triethoxysilylpropyl)tetrasulfide (TESPT) [171,172]. 

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