Showing papers on "Transfer agent published in 2018"
TL;DR: A dual-concurrent atom transfer radical polymerization/reversible addition-fragmentation chain-transfer (ATRP/RAFT) system is used to control aradical polymerization by electrochemical reduction of small amount of copper complexes in the presence of a chain transfer agent (CTA).
Abstract: A dual-concurrent atom transfer radical polymerization/reversible addition-fragmentation chain-transfer (ATRP/RAFT) system is used to control a radical polymerization by electrochemical reduction of small amount of copper complexes in the presence of a chain transfer agent (CTA). Electrochemical ATRP conditions provide a continuous supply of radicals, while the CTA aids the control over molecular weight and dispersity of poly(n-butyl acrylate), even in the presence of low ppm amounts of catalyst. The polymerization could be turned "on" and "off" by shifting electrolysis potential. With as low as 10 ppm of Cu catalyst, addition of only 2% CTA (with respect to the ATRP initiator) improves control by decreasing dispersity from Ð = 1.41 to Ð = 1.25.
23 citations
TL;DR: In this article, ruthenium triazole -arene complexes were used for catalytic alkenes cleavage using mesoporous silica materials and showed enhanced activity when compared to conventional homogeneous systems even when operating at relatively low catalyst loading.
Abstract: The oxidative cleavage of alkenes was performed using ruthenium triazole -arene complexes immobilized on mesoporous silica materials. These silica-organometallic hybrid materials were found to show enhanced activity when compared to conventional homogeneous systems even when operating at a relatively low catalyst loading. The enhanced catalytic performance of these heterogeneous systems can be attributed to the mesoporous silica acting as a phase transfer agent in the biphasic catalyst system.
14 citations
TL;DR: In this paper, the effect of potential chain transfer agent (CTA) on microstructure, molecular weight, chain end group and structural, thermal and mechanical properties of poly(E-co-N)s was evaluated.
12 citations
28 Dec 2018
TL;DR: The expansion of the core structures by chain-extension polymerization resulted in the successful preparation of high molecular weight SB-PAMs with apparent molecular weights ranging from 19 to 1250 kDa.
Abstract: Starlike branched polyacrylamides (SB-PAMs) were synthesized using reversible addition-fragmentation chain transfer copolymerization of acrylamide (AM) and N,N'-methylenebis(acrylamide) (BisAM) in the presence of 3-(((benzylthio) carbonothioyl)thio)propanoic acid as a chain transfer agent, followed by chain extension with AM. The amount of incorporated BisAM in the core and the amount of AM during chain extension have been systematically varied. Core structures were achieved by incorporation of total monomer ratios [BisAM]/[AM] ranging from 0.010 to 0.143. The obtained macromolecular chain transfer agents had weight average molecular weights in the range of (2.2-7.8) × 103 Da and polydispersity indices between 1.2 and 15.1. Kinetic experiments were performed to investigate the extent of control of polymerization. Finally, the expansion of the core structures by chain-extension polymerization resulted in the successful preparation of high molecular weight SB-PAMs with apparent molecular weights ranging from 19 to 1250 kDa.
7 citations
TL;DR: Hyper-branched poly(styrene) (HPS) made from copolymerisation of styrene (St) and a branching monomer divinylbenzene (DVB) in the presence of a chain transfer agent n-dodecanethiol (C12SH) was graf...
Abstract: Hyper-branched poly(styrene) (HPS) made from copolymerisation of styrene (St) and a branching monomer divinylbenzene (DVB) in the presence of a chain transfer agent n-dodecanethiol (C12SH) was graf...
5 citations
Patent•
09 Nov 2018
TL;DR: In this article, a ternary copolymerized cationic polyacrylamide colloid product is obtained by prilling the colloid and adding anti-crosslinking agent solution into the colloidal particles for mixing, drying and milling the colloids into powder, after sieving, obtaining powder product of the ternarily copolymized catedric polyacyl polycycled polyacylamide, which has significant hydrolysis resistance property.
Abstract: The invention discloses a preparation method of ternary copolymerized cationic polyacrylamide, including the following steps: stirring to dissolve cationic monomer diallyl dimethyl ammonium chloride,methacrylamide, propyl trimethylammonium chloride, nonionic monomer acrylamide, a metal ion chelating agent, and a chaotropic agent in water, adding a chain transfer agent and an initiating agent in turn after injecting nitrogen for removing oxygen, which evenly mixes the chain transfer agent and initiating agent and reaction liquid by effect of the nitrogen flow to obtain the ternary copolymerized cationic polyacrylamide colloid product, obtaining the colloidal particles by prilling the colloid product, adding anti-crosslinking agent solution into the colloidal particles for mixing, drying and milling the colloidal particles into powder, after sieving, obtaining powder product of the ternary copolymerized cationic polyacrylamide. The ternary copolymerized cationic polyacrylamide has significant hydrolysis resistance property, flocculent property is maintained and improved, the product economy is optimized relative to copolymerized products of MAPTAC and acrylamide. The method is applicable to large kettle production, which is easy to implement industrialization.
4 citations
Patent•
19 Jan 2018
TL;DR: In this article, a mud-resistant type polycarboxylic acid high-performance water-reducing agent and a preparation method thereof were described, which is particularly suitable for materials containing high-content argillaceous sand stone, stone powder, machine-made sand and the like.
Abstract: The invention relates to a mud-resistant type polycarboxylic acid high-performance water-reducing agent and a preparation method thereof. Synthesis raw materials contain an N-vinyl pyrrolidone graft beta-cyclodextrin comonomer. The synthesis raw materials also contain a methyl allyl polyethenoxy ether comonomer, an unsaturated carboxylic acid comonomer, an initiator, a reducing agent, a chain transfer agent, liquid alkali and water. The mass ratio of the synthesis raw materials, namely the methyl allyl polyethenoxy ether comonomer to the unsaturated carboxylic acid comonomer to the N-vinyl pyrrolidone graft beta-cyclodextrin comonomer to the initiator to the reducing agent to the chain transfer agent to the liquid alkali to the water, is (350-400):(28-32):(8-15):(1.5-2.5):(1.0-1.6):(0.8-1.6):(30-45):(430-480). The mud-resistant type polycarboxylic acid high-performance water-reducing agent and the preparation method thereof have the advantages of simple technological process, high dispersing property, remarkable mud-resistant effect, excellent adaptability with cement and the like, and are particularly suitable for materials containing high-content argillaceous sand stone, stone powder, machine-made sand and the like.
4 citations
DOI•
01 Jan 2018TL;DR: In this article, a homogeneous catalyst system based on bis(imino) pyridine iron with the addition of diethyl zinc (DEZ) as alkyd transfer agent to promote immortal copolymerization was presented.
Abstract: Ethylene-norbornene copolymers were synthesized with a homogeneous catalyst system based on bis(imino) pyridine iron with the addition of diethyl zinc (DEZ) as alkyd transfer agent to promote immortal copolymerization. The addition of DEZ did not influence the catalytic activity in copolymerization with 7.5 mmol of norbornene (NB), but in the reactions with 70 mmol, the comonomer promoted an increase of activity. We observed by thermal analysis that the norbornene inserted in the chains promoted an increase in thermal stability of the synthesized material with higher amounts of comonomer, since the temperature of initial degradation was much higher for these copolymers compared to polyethylene. In addition, for the copolymers with 7.5 mmol of norbornene, the DEZ served as alkyd transfer agent, as shown by the gel permeation chromatography analysis, leading to a decrease in both molar mass and polydispersity. The UV-Vis spectra showed that the diethyl zinc did not change the catalytically active center, but only acted as an alkyd transfer agent.
3 citations
Patent•
02 Feb 2018
TL;DR: In this article, a normal temperature synthetic polyester polyether polycarboxylic acid water-reducing agent and a preparation method are presented. But the method is not suitable for precast and cast-in-place concrete.
Abstract: The invention discloses a normal temperature synthetic polyester polyether polycarboxylic acid water-reducing agent and a preparation method thereof, wherein the water reducing agent is prepared as follows: at normal temperature in a redox system, esters, ethers and unsaturated carboxylic acids and derivatives thereof are polymerized to form a polymer with the carboxylic acids and derivatives thereof as a backbone, and a chain transfer agent is used for control of the degree of polymerization. Concrete prepared by the water reducing agent has the advantages of good workability, good slump lossresistance, good workability and high strength, and the water-reducing agent is suitable for precast and cast-in-place concrete, reinforced concrete and prestressed concrete for high-speed railways,passenger dedicated lines, industrial and civil buildings, roads, bridges, ports, piers, airports and other engineering construction.
3 citations
Patent•
20 Nov 2018
TL;DR: In this paper, an anti-mud water reducing agent for concrete and a preparation method thereof is presented, which solves the problems that conventional water reducing agents are too high in sensitivity to mud content in aggregates in high mud content concrete application, so that fresh concrete becomes poor in workability, and the slump loss is quickened.
Abstract: The invention provides an anti-mud water reducing agent for concrete and a preparation method thereof. The anti-mud water reducing agent solves the problems the conventional water reducing agent is too high in sensitivity to mud content in aggregates in high mud content concrete application, so that fresh concrete becomes poor in workability, and the slump loss is quickened. The water reducing agent adopts the technical scheme that the water reducing agent belongs to polymer comprising the following components: polyoxyethylene ether containing unsaturated double bonds, unsaturated acid, functional monomer, an oxidizing agent, a reducing agent and a chain transfer agent; the polymer is formed by performing copolymerization on the polyoxyethylene ether containing unsaturated double bonds, unsaturated carboxylic acid and functional monomer in an aqueous solution with the chain transfer agent in the condition of the existence of a redox initiator. The water reducing agent is stable in performance and obvious in dispersion effect, improves the operating performance of concrete, is small in shrinkage of concrete, rustless to reinforcing steel bars, and moderate to gas content, can be synthesized at normal temperature, is short in time consuming, low in energy consumption and simple to operate, and has high market competitiveness.
3 citations
Patent•
12 Jan 2018
TL;DR: In this paper, a single site transition metal complexes (such as quinolinyldiamide transition metal complex), an activator, and a metal hydrocarbenyl transfer agent (preferably an aluminum vinyl-transfer agent) are disclosed for use in alkene polymerization.
Abstract: Catalyst systems with single site transition metal complexes (such as quinolinyldiamide transition metal complexes), an activator, and a metal hydrocarbenyl transfer agent (preferably an aluminum vinyl-transfer agent) are disclosed for use in alkene polymerization.
TL;DR: In this paper, a coordinated chain transfer copolymerization of ethylene and styrene was successfully achieved using an ansa-bisfluorenyl neodymium complex, a dialkylmagnesium as a chain transfer agent and di-n-butylether (Bu2O) as a co-solvent.
Patent•
23 Nov 2018
TL;DR: In this paper, a synthesis method of ultra-low molecular weight polyvinyl alcohol using a solution polymerization method is presented. But the method is not suitable for high temperature conditions such as polymerization temperature, initiating agent concentration and chain transfer agent consumption.
Abstract: The invention discloses a synthesis method of ultra-low molecular weight polyvinyl alcohol. The ultra-low molecular weight polyvinyl alcohol is prepared by using vinyl acetate as raw materials, methanol as a solvent and carbon tetrachloride as a chain transfer agent by a solution polymerization method; the polymerization degree influence conditions such as polymerization temperature, initiating agent concentration and chain transfer agent consumption are discussed; then, an orthogonal experiment is used for optimization; the optimized synthesis process conditions of the ultra-low molecular weight polyvinyl alcohol are obtained; the PVAc with the polymerization degree being 100 to 600 is finally synthesized; alcoholysis is performed to obtain the PVA with the molecular weight being 5000 to25000; the yield is high; the synthesis process is simple; good popularization and application values are realized in the field of degradable biological materials.
Patent•
11 Dec 2018
TL;DR: In this article, a method for achieving active and controllable free radical polymerization under an air condition is presented, which consists in the following step: initializing a polymerization reaction on a monomer and a reversible addition-chain transfer agent by using an initiator, namely triethylborine, thereby obtaining a polymer of a target molecular weight and narrow molecular weight distribution.
Abstract: The invention belongs to the technical field of polymer synthesis and in particular discloses a method for achieving 'active'/controllable free radical polymerization under an air condition. The method comprises the following step: initializing a polymerization reaction on a monomer and a reversible addition-chain transfer agent by using an initiator, namely triethylborine, thereby obtaining a polymer of a target molecular weight and narrow molecular weight distribution.
Patent•
06 Mar 2018
TL;DR: In this paper, a water-retention type concrete water reduction agent and a preparation method thereof are presented. But the preparation method comprises the following steps: putting a polyether macromonomersolution into a first reactor, heating, adding a chain transfer agent and an original bulk unsaturated acid monomer, uniformly stirring, and adding a catalyst, dropwise adding an oxidant solution, therest unsaturated monomer solution and a reduction agent solution so as to obtain a polycarboxylate water reducing agent; after the drop-wise adding is completed, putting a
Abstract: The invention relates to a water-retention type concrete water reduction agent and a preparation method thereof. The preparation method comprises the following steps: putting a polyether macromonomersolution into a first reactor, heating, adding a chain transfer agent and an original bulk unsaturated acid monomer, uniformly stirring, and adding a catalyst, dropwise adding an oxidant solution, therest unsaturated monomer solution and a reduction agent solution so as to obtain a polycarboxylate water reducing agent; after the dropwise adding is completed, putting a sulfonated hydroxymethylatedmelamine solution and ammonium persulfate into the first reactor, and performing polymerization reaction, thereby obtaining the water reducing agent. The invention further provides the water reducingagent prepared by using the method. The water reduction rate of the water reducing agent is as high as 25-30%, various properties of concrete are not affected, the amount of large bubbles of newly mixed concrete is also reduced, particularly the viscosity of newly mixed low-grade cementing material-poor concrete is increased, and concrete bleeding possibility is effectively reduced.
Patent•
18 May 2018
TL;DR: In this paper, a preparation method of polyacrylate dispersing agent is described, which comprises the following steps: an aqueous solution I with equal concentration is prepared from triethylenetetetramine, and an an equal solution II with equal amount of acrylate; the two solutions are added to a three-mouth flask in a ratio of 1:3, the threemouth flask is equipped with a stirring device and a reflex condensation device, a certain quantity of an initiator and a certain quantities of a chain transfer agent are added, the
Abstract: The invention discloses a preparation method of a polyacrylate dispersing agent. The method comprises the following steps: an aqueous solution I with equal concentration is prepared from triethylenetetramine, and an aqueous solution II with equal concentration is prepared from acrylate; the two aqueous solutions are added to a three-mouth flask in a ratio of 1:3, the three-mouth flask is equippedwith a stirring device and a reflex condensation device, a certain quantity of an initiator and a certain quantity of a chain transfer agent are added, the mixture is heated to 70-85 DEG C, and refluxstirring is performed for 3-6 h at the stirring rate of 150-320 r/min; the temperature is reduced to room temperature, discharge is performed, and the dispersing agent is obtained. The dispersing agent prepared with the method has good dispersion performance, and the problem that the dispersion effect on small inorganic particles is not ideal can be solved; in the preparation method, a polymericmonomer, the initiator and a molecular weight regulator are fed once and heating is performed directly, so that process steps are reduced greatly, a large quantity of manpower and material resources are saved, cost is saved, and relative molecular weight of a solvation chain can be controlled conveniently by changing dosages of the initiator and the chain transfer agent.
Patent•
26 Oct 2018
TL;DR: In this paper, a synthesis method of monoglyceride containing a phase transfer agent is presented, which includes the following technological steps: adding 25 to 40 weight percent of natural oil, 54 to 73 weight amount of glycerol and 1 to 3 weight percent phase transfer agents into a 500mL three-mouth flask; stirring for 10 to 30min to sufficiently mix the natural oils, the glycerols and the phase-transfer agent; pre-heating to 50 to 80 DEG C; dropwise adding 1to 3 weight percentage of an alkaline catalyst; heating
Abstract: The invention provides a synthesis method of monoglyceride containing a phase transfer agent. The synthesis method comprises the following technological steps: adding 25 to 40 weight percent of natural oil, 54 to 73 weight percent of glycerol and 1 to 3 weight percent of the phase transfer agent into a 500mL three-mouth flask; stirring for 10 to 30min to sufficiently mix the natural oil, the glycerol and the phase transfer agent; pre-heating to 50 to 80 DEG C; dropwise adding 1 to 3 weight percent of an alkaline catalyst; heating to 180 to 200 DEG C and stirring and reacting for 2 to 6h; afterreaction is finished, adding an acid solution and neutralizing the pH (Potential of Hydrogen) of a reaction system to 6 to 7; rapidly cooling to 70 to 80 DEG C to obtain a monoglyceride crude product; S4: washing with water and filtering to obtain a white solid; finally, separating and purifying through molecular distillation to obtain the high-purity monoglyceride. The synthesis method providedby the invention has the beneficial effects that the miscibility of the oil and the glycerol is increased, the reaction is promoted, the conversion rate of the monoglyceride is high and the purity ofa product is high.
Patent•
26 Jan 2018
TL;DR: In this paper, a double-side chain polycarboxylate superplasticizer and a preparation method for concrete is presented, which has the advantages of low mixing amount, high water-reducing rate, good slump retaining property and the like when being applied to concrete, so that the production cost of concrete can be greatly saved.
Abstract: The invention discloses a double-side chain polycarboxylate superplasticizer and a preparation method thereof. The double-side chain polycarboxylate superplasticizer is prepared by the following steps: generating conventional free radical polymerization by virtue of polyether monomers and (methyl) allyl chloride under the actions of an initiator and a chain transfer agent, so as to obtain a prepolymer; generating nucleophilic substitution by virtue of the prepolymer and sodium hydrosulfide, so as to obtain a macromolecular chain transfer agent with sulfydryl; and finally, carrying out free radical polymerization by virtue of the macromolecular chain transfer agent, a monomer A and a monomer B. The preparation method has the beneficial effects that by producing through a one-pot method, nowaste material is produced, the process is simple, and the large-scale production is promoted; the product has the advantages of low mixing amount, high water-reducing rate, good slump retaining property and the like when being applied to concrete, so that the production cost of the concrete can be greatly saved; the double-side chain polycarboxylate superplasticizer has low sensitivity to the types of cements and good tolerance to sandstone aggregates with high silt content, and the viscosity of high-strength concrete can be effectively reduced.
Patent•
28 Dec 2018
TL;DR: In this paper, a concrete slump retaining agent with high adaptability and a preparation method for copolymerization with a polyether macromonomer, unsaturated sulfonic acid salt and unsaturated carboxylic acid as a comonomer and an initiator and a chain transfer agent as a molecular regulator is provided.
Abstract: A concrete slump retaining agent with high adaptability and a preparation method thereof are provided The concrete slump retaining agent is prepared by copolymerization with a polyether macromonomer,unsaturated sulfonic acid salt and unsaturated carboxylic acid as a comonomer and an initiator and a chain transfer agent as a molecular regulator The mass ratio of the components is that polyethermacromonomer: unsaturated sulfonate: unsaturated carboxylic acid: chain transfer agent: initiator: deionized water= (60-120): (2-10): (1-12): (05-4): (05-3): (95-125) The amount of dilution water meets the requirement that the solid content can reach 40% after the dilution water is added into products for dilution at the end of the reaction The preparation method of the concrete slump retaining agent with high adaptability is further provided The agent is not sensitive to temperature and alkali content in concrete, and solves the problem that the existing concrete slump retaining agent issensitive to the temperature and the alkali content
Patent•
08 May 2018
TL;DR: In this article, a polycarboxylic acid water reducing agent can also be obtained by polymerizing by adding initiating agents dropwise at the temperature of 60 to 80 DEG C.
Abstract: The invention relates to a synthesizing method for a polycarboxylic acid water reducing agent. The synthesizing method comprises the following steps: firstly, adding water and monomers A into a reactor with a stirrer, stirring, and dissolving to obtain a mixed liquid 1; secondly, adding an oxidant into the mixed liquid 1 at normal temperature, stirring uniformly, and continuously adding acrylic acid aqueous solution, a chain transfer agent and a reducing agent dropwise to obtain a mixed liquid 2, wherein the dropwise adding time is 2 to 3 hours; thirdly, after the acrylic acid aqueous solution, the chain transfer agent and the reducing agent are added dropwise, preserving heat of the mixed liquid 2 for one hour, and finally, adding water until the solid content is 40 percent. The polycarboxylic acid water reducing agent can also be obtained by polymerizing by adding initiating agents dropwise at the temperature of 60 to 80 DEG C. The water reducing agent obtained by the synthesizing method is high in water reducing rate, good in slump protecting property, good in enhancing effect, easy to produce, environmentally friendly, low in cost and wide in application; maleic anhydride and polyols which are used for synthesizing polyether monomers are widely applied ordinary chemical raw materials, can be produced by a plurality of manufacture factories, and are low in cost, so that thecost of the monomers can be greatly reduced, and the cost performance of the polycarboxylic acid water reducing agent is improved.
Patent•
28 Sep 2018
TL;DR: In this paper, a polymer surface modified calcium sulphoaluminate expanding agent was proposed to improve the crack resistance of concrete by prehomogenization treatment and a polymerization reaction process.
Abstract: The invention discloses a polymer surface-modified calcium sulphoaluminate expanding agent, which is prepared from a calcium sulphoaluminate expanding agent clinker, part of neutralized unsaturated carboxylic acid, an unsaturated amide monomer, a chain transfer agent, an initiator, a crosslinking agent and the like. The invention further provides a preparation method of the polymer surface-modified calcium sulphoaluminate expanding agent. The preparation method comprises raw material prehomogenization treatment and a polymerization reaction process. Under the condition of different water-binder ratios, the polymer surface-modified calcium sulphoaluminate expanding agent still can be continuously moisturized to keep certain humidity, and hydration for an expanding source is continuously implemented, so as to provide enough high expansion energy and enough actual time for compensating contraction to achieve a good retraction contraction effect and improve the crack resistance of concrete.
Patent•
23 Feb 2018
TL;DR: In this article, the phosphate-ester dispersing agent is used in a coating and ink, which has a wide consistency and excellent dispersion stability, and is low in color paste viscosity, good in paint-film showing color and high in luster.
Abstract: The invention relates to a phosphate-ester dispersing agent. The phosphate-ester dispersing agent comprises a free radical polymer precursor shown in the chemical formula (1) and reaction products ofa phosphated reagent (The formula is defined in the description), wherein a raw material of the free radical polymer precursor shown in the chemical formula (1) is prepared from a monomer A, a monomerB, an initiating agent and a chain transfer agent, the monomer A is alkyl methacrylate or alkyl acrylate, the monomer B is an ethylenic-bond unsaturated monomer with 5-80 carbon atoms and a polyethersegment, and in the chain transfer agent (The formula is defined in the description), m is an integer between 2 and 12. When the phosphate-ester dispersing agent is used in a coating and ink, the phosphate-ester dispersing agent has the wide consistency and the excellent dispersion stability, and is low in color paste viscosity, good in paint-film showing color and high in luster.
Patent•
26 Jun 2018
TL;DR: In this paper, a hydrophobic group-modified hyperbranched polycarboxylate water reducing agent and a preparation method and application thereof are discussed, where side chains containing hydrophilic groups are introduced on the basis of a conventional polycar boxylate WRS agent, and meanwhile a hyperbranchhed structure is formed by using a chain transfer agent with polyfunctionality.
Abstract: The invention belongs to the field of cement additives, and discloses a hydrophobic group-modified hyperbranched polycarboxylate water reducing agent and a preparation method and application thereof.Side chains containing hydrophobic groups are introduced on the basis of a conventional polycarboxylate water reducing agent, and meanwhile a hyperbranched structure is formed by using a chain transfer agent with polyfunctionality; on the one hand, the repulsive force among cement particles which are adhered to water reducing agent molecules can be enhanced, on the other hand, the spatial size ofthe water reducing agent can be improved by the hyperbranched structure, so that the stereo-hindrance effect of the water reducing agent molecules is enhanced, and the purpose of improvement of the overall performance of the water reducing agent can be achieved through the improvement of fluidity of cement paste. When the solid content is 40%, reference cement has paste fluidity of more than 285 mm and air content of beyond 2.5% at a water-cement ratio of 0.35 and a water-reducing agent dosage of 0.6%, and meanwhile the compressive strength of the cured sample is ensured.
Patent•
27 Jul 2018
TL;DR: In this article, a synthetic method for a polycarboxylic acid high-performance water reducing agent, which belongs to the field of cement concrete water reducing agents, is described. But the method is not suitable for large-scale production.
Abstract: The invention discloses a synthetic method for a polycarboxylic acid high-performance water reducing agent, and belongs to the field of cement concrete water reducing agents. The method comprises thefollowing steps: mixing unsaturated polyoxyethylene ether or an unsaturated polyester macromonomer, an unsaturated carboxylic acid or an unsaturated acid anhydride small monomer, a chain transfer agent and an initiator, performing mechanical ball milling for a mechanochemical reaction, taking out the obtained product, adding water for dissolution, and adjusting a pH value at 6-8 by using an alkaline liquid to prepare the polycarboxylic acid high-performance water reducing agent. The method provided by the invention has a simple preparation process, is operated at room temperature, and has short time and low costs; the product has a high solid content, can greatly reduce energy consumption and is convenient for transportation and use; and the prepared polycarboxylic acid high-performance water reducing agent has the characteristics of a high water-reducing rate and good slump loss resistance, and is suitable for industrialized large-scale production.
Patent•
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06 Dec 2018
TL;DR: In this article, a cell transfer agent comprising a composite particle coated by a sugar chain polymer was presented, where the composite particle consisting of an apatite comprising phosphate, carbonic acid, and calcium.
Abstract: The present invention is a cell transfer agent comprising a composite particle coated by a sugar chain polymer wherein the composite particle consisting of an apatite comprising phosphate, carbonic acid, and calcium.
Patent•
06 Feb 2018
TL;DR: In this article, the main catalyst, an auxiliary catalyst, and a chain transfer agent are used for poly alpha-olefin with controllable molecular weight, and the method for catalyzing polymerization of long-chain alpha -olefin is described.
Abstract: The invention provides catalyst composition for polymerization of long-chain alpha-olefin and a method for catalyzing polymerization of long-chain alpha-olefin by the catalyst composition. The catalyst composition comprises a main catalyst, an auxiliary catalyst and a chain transfer agent, wherein the main catalyst has the structure shown in the following description, wherein X denotes halogen, R -R are the same or different and independently selected from at least one of hydrogen, halogen, C1-C20 hydrocarbonyl and C4-C10 heterocyclic groups respectively; the auxiliary catalyst is selected from at least one of alkylaluminoxane, aryl boron and borate; the chain transfer agent is selected from trialkylaluminium and/or dialkylzinc. The method for catalyzing polymerization of long-chain alpha-olefin comprises steps as follows: long-chain alpha-olefin, the main catalyst, the auxiliary catalyst and the chain transfer agent make contact in the presence of inert gas for a polymerization reaction. The catalyst composition has higher catalytic activity and good thermal stability when catalyzing chain transfer polymerization of alpha-olefin and is used for synthesis of poly alpha-olefinwith controllable molecular weight.
Patent•
22 Jun 2018
TL;DR: In this paper, a carbon black-modified polycarboxylate water reducing agent, a preparation method and application of thereof, is described, where the water reducing agents are prepared from a component A and a component B, wherein the component A is prepared from the following components in parts by weight: 10 parts of carbon black particles, 0.2 to 0.4 part of a hydroxyl-containing azoic compound, 0 3 to 1.3 part of an acid binding agent, 45 to 80 parts of micromolecular unsaturated carboxylic
Abstract: The invention belongs to the field of cement additives, and discloses a carbon black-modified polycarboxylate water reducing agent, a preparation method and application thereof. The water reducing agent is prepared from a component A and a component B, wherein the component A is prepared from the following components in parts by weight: 10 parts of carbon black particles, 0.2 to 0.4 part of a hydroxyl-containing azoic compound, 0.3 to 1.0 part of a micromolecular acyl chloride compound, 0.1 to 0.5 part of an acid binding agent, 45 to 80 parts of micromolecular unsaturated carboxylic acid, 150to 200 parts of unsaturated polyether monomers, 0.2 to 0.5 part of a pyrolysis catalyst and 0.1 to 0.3 part of a chain transfer agent; the solid content of a carbon black-modified polycarboxylate water reducing agent product is 40 percent; the cement paste fluidity and the compressive strength of cement can be improved; meanwhile, the sensitivity to soil is reduced; construction and application are facilitated better.
Patent•
04 Dec 2018
TL;DR: In this paper, a controllable/living radical polymerization method controlled by organic antimony in ionic liquid is presented, which can be carried out at a low temperature, so that energy is saved.
Abstract: The invention discloses a controllable/living radical polymerization method controlled by organic antimony in ionic liquid The method takes ionic liquid as a reaction medium, an oxidizing agent and an organic antimony compound are added, monomer polymerization in a protective gas atmosphere is performed to obtain a polymerization product, wherein the organic antimony compound is used as a chain transfer agent and also as a reducing agent and can be subjected to oxidation-reduction reaction with the oxidizing agent to initiate polymerization, so that the polymerization can be carried out at alow temperature; and meanwhile, the ionic liquid is adopted as a reaction medium, so that the polymerization is more controllable The method can be carried out at a low temperature, so that energy issaved, and the method has potential industrial application value and promotes the industrial production of free radical living polymerization
Patent•
22 Jun 2018
TL;DR: In this paper, a high-slump-loss-resistant polycarboxylic acid high-performance water reducing agent was proposed, which overcomes the defects of poor slump-loss resistance, poor adaptability, long coagulation time and the like of common water reducing agents.
Abstract: The invention discloses a high-slump-loss-resistant polycarboxylic acid high-performance water reducing agent. The water reducing agent is prepared from the following raw materials in parts by weight:allyl polyoxyethylene ether, dihydroxyketone, sodium lignin sulfonate, unsaturated methyl alkenyl polyoxyethylene ether, a chain transfer agent, unsaturated octadecyl betaine, polyethylene glycol acrylate, sodium acrylate, an aminoaryl sulfonating agent, a polymer, oxalic acid, glycidol, a dilute alkali solution, an antifreezing agent and an initiator. The high-slump-loss-resistant polycarboxylicacid high-performance water reducing agent overcomes the defects of poor slump-loss resistance, poor adaptability, long coagulation time and the like of common water reducing agents, and has the advantages of high slump-loss resistance, high water reducing rate and short coagulation time.
Patent•
21 Dec 2018
TL;DR: In this paper, a method for catalytically synthesizing a polycarboxylate superplasticizer in the presence of a nickel salt is described. But the method is characterized by comprising the following steps: preparing raw material macromonomer, micro monomer, a chain transfer agent, a reducing agent, an oxidizing agent, catalyst and water; mixing the micro-monomer, the chain transfer agents and water to prepare a solution A; mixing, dropwise adding the solution A and the solution B at a constant rate, wherein the total time of dropwise addition
Abstract: The invention discloses a method for catalytically synthesizing a polycarboxylate superplasticizer in the presence of a nickel salt. The method is characterized by comprising the following steps: preparing raw material macromonomer, micro monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water; mixing the micro monomer, the chain transfer agent and water to prepare a solution A; mixing the reducing agent, the catalyst and water to prepare a solution B; adding the macromonomer and water to a reactor with a thermometer, heating and stirring, adding the oxidizing agent when the temperature is up to 45-50 DEG C and the macromonomer is completely dissolved, mixing, dropwise adding the solution A and the solution B at a constant rate, wherein the total time ofdropwise addition and thermal reaction is 2 to 3 hours, and cooling the material after reaction to room temperature, thereby obtaining the polycarboxylate superplasticizer. The method has the advantages of low reaction temperature, high production efficiency, low production cost, good product dispersing performance and moisture retention performance, industrial production and high practicability,and the polycarboxylate superplasticizer is particularly suitable for preparation of cement-based building materials.