Showing papers on "Precipitated silica published in 2015"

Characterization of Effects of Silica Nanoparticles on (80/20) PP/PS Blends via Nonlinear Rheological Properties from Fourier Transform Rheology

Abstract: Effects of silica nanoparticles with different natures (hydrophilicity and hydrophobicity) on (80/20) PP/PS blends were investigated via linear and nonlinear rheological properties. The hydrophilic silica nanoparticle was fumed silica OX50 while the two hydrophobic ones were precipitated silica D17 and fumed silica R202. SEM images revealed that hydrophilic OX50 could not improve morphological properties of the blends. On the other hand, the two hydrophobic silica nanoparticles (R202 and D17) improved morphological properties. TEM examination showed that OX50 silica nanoparticles aggregated inside PS droplets, thereby making breakup of PS (dispersed) phase into smaller sizes more difficult. D17 and R202 improved morphological properties regardless of the different droplet size reduction mechanisms, and rheological properties improved as a result. Both linear rheological properties from SAOS (small-amplitude oscillatory shear) tests and nonlinear rheological properties from LAOS (large-amplitude oscillator...

Effect of moisture on the heat capacity and the regeneration heat required for CO2 capture process using PEI impregnated mesoporous precipitated silica

Abstract: In this study, we report the effect of the moisture of polyethylenimine (PEI) impregnated mesoporous precipitated silica used for CO2 adsorption on the heat capacity and the heat required to regenerate the adsorbent. The results indicate that the heat capacity of the absorbent increases as its moisture content increases. The increase in moisture results in the rise of the vaporization heat of water and the elevated heat capacity results in higher sensible heat. For these reasons, the total regeneration heat required for CO2 capture process increases significantly. The adsorbent has a maximum CO2 adsorption capacity at 75 °C. CO2 capture process using PEI impregnated mesoporous precipitated silica requires a minimum energy to regenerate the adsorbent; it reduces 46% of the energy compared to a process using an aqueous MEA 30 wt%, as the process operates at 75 °C.

Antioxidation efficiency and reinforcement performance of precipitated-silica-based immobile antioxidants obtained by a sol method in natural rubber composites

Abstract: Tetraethoxysilane-40 (TEOS) was hydrolyzed in an alkaline environment to prepare a sol precursor consisting of large amounts of silicic acid oligomers, and then the silicic acid oligomer was grafted with 4-aminodiphenylamine (RT) which was the intermediate of antioxidant-4010NA (AO) via silane coupling agent 3-glycidoxypropyltrimethoxysilane (KH-560), generating the precipitated-silica-based antioxidant (P-RT) through the condensation polymerization. A Fourier transform infrared spectroscopy (FTIR) test demonstrated that RT has been successfully grafted onto the surface of precipitated silica. Thermogravimetric analysis (TGA) results exhibited the high grafting efficiency of this sol-grafting method. The massive grafted antioxidant groups took the same role as the traditional surface modifier bis(3-triethoxysilylpropyl)tetrasulfide (TESPT). According to the results of tensile tests, the reinforcement performance of P-RT was better than that of the silica modified by TESPT in a natural rubber matrix. Oxidation induction time (OIT) tests and accelerated aging tests revealed that P-RT possessed much better anti-oxidative and anti-migratory efficiency than that of the corresponding low molecular counterpart (4010NA).

Composition essentially free of water and comprising at least one spore forming fungal biological control agent, a polyether-modified trisiloxane and fumed or precipitated silica

Abstract: The present invention relates to a liquid composition comprising at least one biological control agent wherein said biological control agent is spores of a spore forming fungus, a polyether-modified trisiloxane and fumed silica or precipitated silica, wherein said composition is essentially free of water, said composition being useful in plant protection.

Ceramic fire-resistant polyolefin composition and preparation method thereof

Abstract: The invention relates to a ceramic fire-resistant polyolefin composition and a preparation method thereof. The ceramic fire-resistant polyolefin composition is prepared from the following components in parts by weight: 100 parts of polyolefin, 20-30 parts of precipitated silica, 15-25 parts of mica powder, 10-50 parts of silica powder and/or glass powder, 10-40 parts of kaolin, 0.5-1.5 parts of a silane coupling agent and 0.5-2 parts of a catalyst. The invention also provides a method for preparing the ceramic fire-resistant polyolefin composition.

Preparation of polyethylenimine impregnated mesoporous precipitated silica for CO2 capture

Abstract: In this study, a novel and inexpensive CO 2 adsorbent has been prepared by impregnating polyethyleneimine (PEI) onto mesoporous precipitated silica. The study indicates that the CO 2 adsorption capacity of the prepared adsorbent increases with the increase in PEI loading. The maximum adsorption capacity of adsorbent can be achieved at 75 o C. In pure CO 2 , at 75 o C and 1 bar, adsorbent containing 60% PEI can adsorb 199.6 mg of CO 2 /g. The adsorption capacity of an adsorbent impregnated with 55% PEI (PEI-MPS-55) measured at the heat equilibrium reduced from 128 mg/g to 117 mg/g and 101 mg/g as CO 2 concentration varies from 100 to 15% and 4%, respectively. The adsorption heat calculated ranges from 68─75 kJ/mole of CO 2 . The cyclic adsorption-desorption studies revealed that the adsorbent is relatively stable; the CO 2 loading was not changed after 20 cycles of adsorption/regeneration at 75/90 o C. Keywords : Adsorption capacity; CO 2 capture; Regeneration; Adsorbent; Precipitated silica.

Rubber prepared with pre-treated precipitated silica and tire with component

Abstract: The invention relates to a rubber composition prepared with pre-treated precipitated silica and tire with component comprised of such rubber composition. The rubber composition is comprised of at least one diene-based elastomer and said pre-treated precipitated silica together with a sulfur cure package comprised of elemental sulfur together with 1,6-bis (N,N′-dibenzylthiocarbamoyldithio)-hexane crosslinking agent and sulfenamide accelerator.

Effects of Nano-silica (NS) Additions on Durability of SCC Mixtures

Abstract: In this study, three different types of nano-silica were applied in self-compacting concrete (SCC), one produced by the controlled dissolution of the olivine mineral and two having similar particle size distributions (PSD), but produced through two different processes: fumed powder nano-silica and precipitated silica in colloidal suspension. The influence of the nano-silica on SCC was investigated with respect to the properties of the concrete in fresh (workability) and hardened state (durability properties). Additionally, the densification of the microstructure of the hardened concrete was analyzed by SEM and EDS techniques. The obtained results demonstrate that an efficient use of nano-silica in SCC can improve its durability properties. Considering the reactivity of the different nano-silica studied, the colloidal type showed a higher reactivity at early age, which influenced the final SCC properties.

Process for the preparation of precipitated silicas, precipitated silicas and their uses, in particular for the reinforcement of polymers

Abstract: The invention relates to a process for the preparation of a novel precipitated silica, wherein: a silicate is reacted with an acidifying agent, so as to obtain a silica suspension; said silica suspension is filtered, so as to obtain a filter cake; said filter cake is subjected to a liquefaction operation, optionally in the presence of an aluminium compound; wherein at least one polycarboxylic acid is added to the filter cake, during or after the liquefaction operation. It also relates to a novel precipitated silica and to its uses.

Preparation method of silica gel with high flame retardant rating

Abstract: The invention discloses a preparation method of silica gel with high flame retardant rating. The silica gel with high flame retardant rating is prepared by mixing the following raw materials in parts: a raw material A: methyl vinyl silicon rubber; a raw material B: methyl vinyl silicon rubber; a raw material C: precipitated silica; a raw material D: hydroxyl silicon oil; a raw material E: dimethyl diethoxy silane; a raw material F: zinc stearate; a raw material G: stearic acid; a raw material H: methyl silicone oil; a raw material I: aluminum hydroxide; a raw material J: zinc stannate; a raw material K: vinyl trimethoxy silane; a raw material L: platinum water; a raw material M: benzotriazole; a raw material N: ferric oxide; a raw material P: magnesium oxide; and a few of raw material Q: curing agent. The silica gel raw material prepared by mixing the raw materials is excellent in flame retardant performance which can reach 5VB and 5VA of UL94 flame retardant rating.

Resin molding sand with characteristics of high heat-resistance and gas permeability, and preparation method thereof

Abstract: The invention relates to resin molding sand with characteristics of high heat-resistance and gas permeability, wherein the resin molding sand is prepared from the following raw materials by weight: 2-4 parts of desulfurized gypsum, 5-7 parts of turpentine oil, 3-5 parts of carbon fibers, 8-13 parts of precipitated silica, 2-3 parts of hydrogenated rosin, 1-1.4 parts of cobalt oxide, 20-25 parts of calcined aluminum hydroxide, 1-1.5 parts of Na2O, 40-50 parts of pit mud, 70-80 parts of knar clay, 3-4 parts of a furan resin, 100-120 parts of clay, a proper amount of water, and 20-30 parts of an auxiliary agent. According to the resin molding sand of the present invention, the clay and the knar clay are adopted so as to provide advantages of suitable particle size, good gas permeability, good fluidity and good dispersion, the carbon fibers, the precipitated silica and the calcined aluminum hydroxide are added so as to increase the strength and the heat resistance of the molding sand particles, the cast surface is smooth, the shakeout is not easily generated, and the recycling can be achieved.

Preparation method of modified nano zinc oxide

Abstract: The present invention discloses a preparation method of modified nano zinc oxide. The preparation steps of the surface precipitated silica are as follows: 1) immersing the non-modified nano zinc oxide in n-hexane solvent of methyl silicone oil, and stirring to prepare a mixed solution; 2) subjecting the mixed solution to evaporation to dryness, and drying in an oven to obtain methyl silicone oil-modified nano zinc oxide; and 3) conducting high temperature roasting on the obtained methyl silicone oil- modified nano-zinc oxide in a muffle furnace so as to prepare the nano zinc oxide with silica deposited on the surface. The invention has the advantages that: 1, silicon deposition modification on the nano ZnO surface inhibits the dissolution of nano zinc oxide and improves dispersion of the nano zinc oxide; and 2. further, bond reaction of citric acid on the hydroxy on the surface of the nano zinc oxide keeps the nano zinc oxide particles from agglomeration and improves the dispersion of nano zinc oxide.

Novel method for preparing precipitated silicas, novel precipitated silicas and the uses of same, in particular for reinforcing polymers

Abstract: The invention concerns a novel method for preparing a precipitated silica, involving the following steps: - reacting a silicate with an acidifying agent in order to obtain a suspension of precipitated silica, - filtering said suspension of precipitated silica, so as to obtain a filtration cake, - subjecting said filtration cake to a spalling operation, - after the spalling operation, carrying out a step of drying, characterised in that at least one polycarboxylic acid is added to the filtration cake during or after the spalling operation. It also concerns novel precipitated silicas and the uses of same.

Silica products from geothermal fluids by reverse osmosis

Abstract: The invention concerns a method and apparatus for producing silica concentrates from geothermal fluids containing at least 300 ppm silica, by passing the fluid at a temperature above 80°C. and at a pH reduced to between 4.0 and 7.5 through a reverse osmosis membrane. In the diagram, geothermal fluid (1) is passed to a separator (2) to be flashed to produce steam (3) and separated geothermal water (SGW) (4). The SGW (4) is passed to a heat exchanger (5) then inlet pump (7). Acid is introduced to the geothermal fluid flow at a dosing means (6) to reduce the pH and an anti-scalant may also be introduced. The geothermal fluid is then passed to a reverse osmosis unit (8) to produce a concentrate (9) and a permeate (10). Following reverse osmosis, the concentrate and permeate may be treated with other processes to produce the desired product and concentration. For example, if precipitated silica is produced, the concentrate is passed to a curing tank (11) and to a thickener (12). The precipitated silica is collected (13) while the retained fluid is removed (14).

Powder brightener for improving surface gloss of mortar

Abstract: The present invention provides a powder brightener for improving surface gloss of mortar and adding to mortar powder The brightener is prepared by mixing, by weight, 3-13 parts of fatty acids, 15-35 parts of paraffin wax and 37-77 parts of a disperse adsorbent First fatty acids and paraffin are mixed evenly; then the disperse adsorbent is placed in a mechanical mixer; and the mixture of fatty acid and paraffin is added to the mixer in a stirring and spraying mode Fatty acid is one or two selected from linoleic acid and oleic acid; paraffin is one or more selected from liquid paraffin, emulsified polyethylene wax and emulsified paraffin; and the disperse adsorbent is one or more selected from zeolite powder, silica fume, precipitated silica, fumed silica, perlite powder and diatomaceous earth The brightener of the present invention is simple in formula and easy for preparation, can be added to the mortar to not only improve the gloss of mortar but also improve the water resistance of mortar, and is particularly suitable for adding to a tile caulking compound or interior wall putty

High porosity silica-containing microporous sheets

Abstract: A flexible microporous polymer sheet having first and second opposite major surfaces comprises a polymer matrix binding a filler component that exhibits high oil absorption capacity in its initial state before the start of material processing. The polymer matrix includes a polyolefin component and has three-dimensional interconnecting and interpenetrating pore and polymer networks through which the bound filler component is distributed from the first major surface to the second major surface. The polyolefin and filler components are included in amounts that result in a microporous polymer sheet having between about 75% and about 90% porosity and containing less than about 10 wt. % polyolefin component. Preferred polyolefin and filler components include ultrahigh molecular weight polyethylene and high oil absorption precipitated silica, respectively.

Highly dispersible precipitated silica and method of preparation thereof

Abstract: The present invention provides highly dispersible precipitated silica having improved structure and properties for use as reinforcing filler in elastomeric compositions and method of preparation thereof. The present invention further provides an alkaline silicate solution having reduced dielectric constant by digesting biogenic silica source with alkaline solution such that soluble organic compounds present in the biogenic silica source leach into the alkaline silicate solution. The alkaline silicate solution obtained as above is then acidified with a mineral acid under particular conditions of pH, temperature, time etc. to obtain the highly dispersible precipitated silica of the present invention.

Environment-friendly inorganic zinc silicate shop primer and preparation method thereof

Abstract: The invention provides environment-friendly inorganic zinc silicate shop primer and a preparation method thereof. The environment-friendly inorganic zinc silicate shop primer is composed of base paste and a curing agent. The base paste comprises zinc powder, ferrophosphorus powder, titanium dioxide, fumed silica, precipitated silica, absolute ethyl alcohol, deionized water, isopropyl alcohol, inorganic filler, polyhydroxycarboxylic acid amide, polydimethylsiloxane defoamer and benzotriazole inhibiter. The curing agent comprises tetraethoxysilane, absolute ethyl alcohol, silicon resin and weak aqua ammonia. According to the inorganic zinc silicate shop primer, mixed solvent of environment-friendly solvent including the isopropyl alcohol, the deionized water and the absolute ethyl alcohol is used for replacing solvent with large smells and toxicity such as methylbenzene and isopropyl alcohol, so that the health of people is guaranteed, and environmental pollution is reduced. Several types of solvent at different volatilization speeds are selected to be matched, so that the surface of a coating is not dazzled any more. The shop primer is suitable for the surfaces of ships, vehicles, offshore platforms, oil tanks, bridges and steel components to serve as anticorrosion maintenance primer.

Hybrid high temperature insulation

Abstract: According to one aspect, a hybrid high temperature thermal insulation includes a mix of inorganic granules. The granular mix includes at least 70 weight percent porous inorganic granules in the form of expanded perlite, and at most 30 weight percent second porous inorganic granules other than expanded perlite. The hybrid insulation also includes a binder. In example formulations, the second porous inorganic particles may be made from crushed aerogel, from fumed silica, from precipitated silica, or from other substances. The hybrid insulation may be formed into preferred shapes, for example a board shape or a semi-cylindrical shape configured to fit over a round tube of a predetermined diameter.

The effectiveness of a watersoluble synthetic acrylic polymer in enhancing reinforcing action of silica in carboxylated acrylonitrile butadiene rubber latex

Abstract: Carboxylated acrylonitrile butadiene rubber (XNBR) latex was filled with surface modified precipitated silica. Surface modification of silica was affected in an aqueous medium by reacting with a synthetic polymer (SP) containing both hydrophilic and hydrophobic groups. The effectiveness of SP in enhancing reinforcing action of silica in XNBR latex films was evaluated through investigation of mechanical properties of vulcanized latex films cast from XNBR latex compounds filled with modified silica over a range of 5 to 20 phr loadings. Tear strength, which is an important mechanical property in certain latex based products like gloves, of modified silica filled cast films was found to be improved in comparison with that of unmodified silica filled cast films. Tear properties of cast films were continued to increase within the range of filler loadings investigated. An optimization of tensile strength was observed at 15phr filler loading in films containing modified fillers and it exceeds the tensile strength of unmodified filler added films with same loading. Morphological studies performed by scanning electron microscopy illustrated that a better distribution of modified filler particles within the XNBR matrix has occurred which may be a consequence of the discouragement of filler aggregation with surface modification. Surface modification of silica has improved the reinforcement action on XNBR.

Rubber composition containing pre-hydrophobated silica with zinc salt fatty acid processing aid and tire with tread

Abstract: The invention relates to rubber compositions containing at least one diene-based elastomer containing dual functionalized styrene/butadiene elastomers and filler reinforcement for the elastomer(s) comprised of pre-hydrophobated precipitated silica together with processing aid for the pre-treated precipitated silica comprised of zinc salt of fatty acids. The invention further relates to a pneumatic tire with tread comprised of such.

Novel process for the preparation of silicate, novel process for the preparation of precipitated silica

Abstract: The invention relates to a novel process for the preparation of silicate comprising: - reacting rice husk ash with a silicate precursor P1 to obtain a silicate S2 having a SiO 2 /M x O molar ratio MR 2 , in which the precursor P1 is either a silicate S1 having a SiO 2 /M x O molar ratio MR 1 such that MR 2 > MR 1 , or a mixture of sand with metal hydroxide.

Method for blending natural latex and precipitated silica

Abstract: The invention provides a method for blending natural latex and precipitated silica. The method includes the steps: under normal pressure and temperature, stirring and adding organic acid into the natural latex water solution, performing stirring, adding emulsifier for continuing stirring, and maintaining the pH value of the solution at 5.5 to 7.0 in all stirring steps; adding silica slurry, performing mixing and stirring, and maintaining the system PH value at 9 to 10 during the stirring by adding alkali metal hydroxide solution. According to the method, the liquid silica and the natural latex are mixed to help improve the dispersity and uniformity of the silica in rubber, thus a tire made from the blending natural latex and precipitated silica has lower rolling resistance, and less energy is consumed in the blending process.

Agricultural Pesticide Formulations

Abstract: The present invention provides for a granular agricultural pesticide formulation of reduced toxicity and good heat and storage stability containing an insecticidally effective amount of bifenthrin; a carrier selected from the group consisting of precipitated silica, colloidal silica, attapulgite, china clay, talc, kaolin and combination thereof; a surfactant; and a diluent.

Process for the preparation of modified silica, modified silica and its uses, in particular for the reinforcement of polymers

Abstract: The invention relates to a process for the preparation of a modified silica comprising the step of adsorbing at least one polycarboxylic acid on precipitated silica.

A process for the production of precipitated silicas and methods for measuring the early abrasion factor

Abstract: The present invention relates to a process for the preparation of a precipitated silica to give presenting water and alkali and / or alkaline earth metal silicate is added until a pH of 8.0 to 10.8 is established, in this template simultaneously with stirring at 50-95 ° C the alkali and / or alkaline earth metal silicate and an acidifying agent, without interruption of the addition is added to a solids content of greater than 150 g / l is reached, wherein the acidifying agent is added to the shaving head of an additional shear assembly in the precipitation vessel becomes, followed by acidification with an acidifier to a pH value of ≤ 5.0, the solid is separated by filtration and washing, drying and grinding. The present invention also relates to a method for the determination of the early abrasion factor with an abrasion test apparatus being used specimens of cast polymethyl methacrylate.