Precipitated silica

About: Precipitated silica is a research topic. Over the lifetime, 1401 publications have been published within this topic receiving 20992 citations.

Exploring Microcrystalline Cellulose (MCC) as a Green Multifunctional Additive (MFA) in a Typical Solution-Grade Styrene Butadiene Rubber (S-SBR)-Based Tread Compound

Abstract: Multifunctional behavior of microcrystalline cellulose (MCC) was investigated in a typical solution-grade styrene butadiene rubber (S-SBR)-based tread compound in connection with its potential as reinforcing filler as well as processing aid. Optimum physical properties were obtained when the loading of MCC was at 10% of the precipitated silica amount by substituting silica. The presence of MCC in mixes had shown reduction in Mooney viscosity. Peak-power consumption during mixing was also found lower for such mixes. Because of enhanced plasticity, it was possible to reduce aromatic oil dosage by 3 phr (equivalent to 18% of the original oil amount) to get the Mooney viscosity and physicomechanical properties comparable to those of the control compound.

Precipitated silica materials exhibiting high compatibility with cetylpyridinium chloride

Abstract: Precipitated silica comprising porous silica particles having a cumulative surface area for all pores having diameters greater than 500 A of less than 6 m2/g, as measured by mercury intrusion, and a percentage cetylpyridinium chloride (% CPC) Compatibility of greater than about 85%. The precipitated silica product is especially well-adapted for use in dentifrices containing cetylpyridinium chloride, which do not attach to the low surface area silica product in a meaningful level and thus remain available for antimicrobial action. Processes for making the silica product including the introduction of sodium sulfate powder during different process steps in order to enhance such a compatibility with CPC are provided.

Tire with tread of CIS 1,4-polybutadiene rich rubber composition which contains a functional styrene/butadiene elastomer, silica and coupling agent

Abstract: The invention relates to a tire having a tread of a rubber composition comprised of a composite of styrene/butadiene elastomer and functionalized styrene/butadiene elastomer containing an internal silanol and/or siloxy group therein with pendent silanol and/or alkoxy groups of a polymodal (e.g. bimodal) molecular weight distribution, together with at least 30 phr of cis 1,4-polybutadiene rubber and a dispersion in said rubber composition of precipitated silica aggregates and a coupling agent as a bis (3-triethoxysilylpropyl) polysulfide having an average of from only 2 to 2.5 sulfur atoms in its polysulfidic bridge to the exclusion of a bis (3-trialkoxysilylalkyl) polysulfide having an average of greater than 2.5, and particularly greater than 3, sulfur atoms in its polysulfidic bridge. In one aspect, said silica aggregates may be pre-treated to reduce said hydroxyl groups on their surface prior to blending with said silanol and/or siloxy functionalized elastomer. In one aspect, a carbon black contained in the rubber composition may be an electrically conductive carbon black.

Effect of the metal oxide loading on the activity of silica supported MoO3 and V2O5 catalysts in the selective partial oxidation of methane

Abstract: Precipitated silica catalysts loaded with either MoO3 (0.2–4.0 wt%) or V2O5 (0.2–5.3 wt%) have been studied in the selective partial oxidation of methane to formaldehyde with molecular oxygen at 520 °C. The functionality of the SiO2 surface towards the formation of HCHO is significantly promoted by V2O5, while it is depressed by the MoO3.

Solution masterbatch process using fine particle silica for low hysteresis rubber

Abstract: Methods are provided for making a solution masterbatch containing a diene elastomer in an organic solvent and a reinforcing silica filler dispersed therein, comprising the steps of (a) mixing a precipitated silica having an average particle size substantially equivalent to an average particle size of a powdered silica, with a diene elastomer in a first organic solvent; and (b) desolventizing the mixture to form a solution masterbatch preparation. The use of such desolventized solution masterbatches in vulcanizable rubber compounds results in excellent processing characteristics with improved dispersion of fillers, including polymeric nanoparticles. The compounds also demonstrate improved properties, including reduced hysteresis.