TESPT

SBR Cariflex S1215 BR Buna CB 10 Silica, Perkacil KS 408 Zinc oxide Stearic acid Aromatic oil Coupling agent, TESPT Santoflex 6PPD Wax PEG 4000 Perkacit TBBS Perkacit DPG Sulfur... 

Thus, the APDS-modified carbon black provides viscoelastic properties comparable to TESPT-modified silica, which is now well known to be better in terms of hysteresis and hence roUing resistance compared to conventional carbon black. 

FIGURE 35.13 Typical fingerprint of a masterbatch mixing process of a solution-based styrene-butadiene rubber (S-SBR)/Silica/TESPT tread compound on a GK 320E (Harburg Freudenberger) with PES5 rotors. 

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

The compositions of the pure S-SBR compounds are given in Table 6. In the recipe containing TESPT, the amount of sulfur was adjusted to compensate for the presence of sulfur contained in TESPT, to represent equimolar quantities in all cases. For the compounding ingredients, see Table 1. 

Silica EPM SBR SBR rubber alcohol TESPT TESPT ammonia reduced interaction with polymer and itself Mooney viscosity decreased larger pore size the later silica is added Mooney viscosity decreased reduced cure rate substantially reduced bound rubber (85%) 48 28 34 34... 

APES - y-aminopropyllrielhoxysilane APTS - 3-animopropyltriethoxysilane ES - epoxy silane MA- maleic anhydride OMCTS - octamethylcycloethoxysiloxane PDMS - poly(dimethyl siloxane) TESPT -(bis)(triethoxysilylpropyl)- tetrasulfone TOAB - tetraoctylammonium bromide with HAuCh... 

In contrast to carbon black, it is necessary to use a coupling agent to achieve silica elastomers reinforcement. TESPT, triethoxysilylpropyltetrasulfide, is the most widely used coupling agent. 

FIGURE 8.4 TESPT loadings are about one Si(OEt)3 per nm, which roughly corresponds to a complete coverage of silica surface. So, for precipitation silicas with content 6-10 Si-OH/nm, many surface silanols will remain unreacled. 

TESPT is a bifunctional molecule with a triethoxysilyl moiety reactive toward silica s silanols and a polysulfidic moiety that reacts with elastomeric chains. 

Because reaction temperatures are somewhat different, the reaction of TESPT with silica surface mainly occurs during mixing when the reaction of polysulfidic moiety takes place during curing (Hunsche et al., 1997 Gdrl et al.,... 

TESPT, a bifunctional polysulfidic organosilane, was introduced as a coupling agent to improve the reinforcement properties of silicas in rubbers. Use of coupling agents offers the following advantages ... 

In silica reinforcement systems containing TESPT, Wolff has suggested that the reaction is similar when the TESPT/silica intermediate is present instead of sulfur, in which case the crosslinking agent is the polysulfidic sulfur chain. Wolff showed that mercaptobenzothiazyl disulfide (MBTS) reacts with the tetrasulfane group, thus forming 2 mol of the polysulfide ... 

Two major breakthroughs have transformed this facility product into a reinforcing filler that can achieve all carbon black mixes properties with, in addition, a decreased hysteresis of major interest for tire applications. The first step was made in the 1970s by Wolff, who proposed a specific silane coupling agent, the TESPT [11]. The second step arises in the 1990s with an R. Rauline s patent, which introduces the use of specific precipitation silica, elastomers, and mixing conditions to achieve reinforcement [12],... 

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