Abstract:
This invention relates to a method for preparing a star-shaped polycarboxylate superplasticizer by the first esterification step with polyol and (meth)acrylic acid as main reactants and the second polymerization step. In the first step, the star-shaped polymerizable active ends were synthesized by esterification between polyol and (meth)acrylic acid in the presence of catalyst. In the second step, the final star-shaped polycarboxylate superplasticizer was prepared by radical polymerization among the product obtained in first step, unsaturated polyoxyethylene ethers, molecular weight regulator and unsaturated carboxylic acid in the presence of initiator. The production process of this invention exhibits some characteristics including simple, easily controllable, high polymerization degree, low cost and pollution free. The star-shaped molecular structure of polycarboxylate superplasticizer can be achieved through synthesizing active “core” by esterification and “arm” by radical polymerization. It showed better cement paste fluidity and fluidity retention, which manifested as better adaptability to cement and application performance in concrete, than both traditional linear and comb-shaped polycarboxylate superplasticizer at common or lower dosage.
Abstract:
A regulating cementitious material for promoting hydration of Portland cement is provided. The regulating cementitious material may include ingredients by weight as follows: ye'elimite, 27˜68 parts; anhydrite, 29˜68 parts; lithium nitrite, 2˜5 parts; ethylene glycol monoisopropanolamine, 0.14˜0.29 parts; triethanolamine acetate, 0.04˜0.09 parts; and polyglycerol, 0.04˜0.09 parts. An early strength of Portland cement can be improved through a cooperative hydration between minerals and an enhanced solubilization of a complexing agent.
Abstract:
Synthesis and application of an alcohol amine with an extended main carbon chain are provided, belonging to the field of chemical building materials. Under the action of a catalyst, tertiary amine is subjected to a two-step substitution reaction, a hydrolytic reaction and a reducing reaction to obtain a novel alcohol amine (NAA). The novel alcohol amine as provided may have a better grinding aid effect than triethanolamine while is added into cement as a cement grinding aid, and thus has a wide application prospect.
Abstract:
This invention relates to a method for preparing a polycarboxylate superplasticizer by graft copolymerization of fatty acid vinyl ester onto acrylate polymer. In this invention, a type of polycarboxylate superplasticizer by graft copolymerization of fatty acid vinyl ester onto acrylate polymer was synthesized by the processes of polymerization-grafting-alcoholysis-hydrolysis with acrylate and fatty acid vinyl ester as main reactants. In the first polymerization step, the polyacrylate was synthesized by using acrylate as monomer and a certain amount of initiator and molecular weight regulator. In the second graft copolymerization step, the graft polymer with polyacrylate as main chain and poly(fatty acid vinyl ester) as side chain was synthesized by graft copolymerization between polyacrylate and fatty acid vinyl ester. The final polycarboxylate superplasticizer product with polyacrylic acid as main chain and polyvinyl alcohol as side chain was obtained by subsequent alcoholysis and hydrolysis steps. The preparation process of this invention exhibited some characteristics including simpleness, easy controlling, low cost, environmental friendliness and pollution free. The fatty acid vinyl ester was as a reactant instead of conventional polyethylene glycol macromonomer, which enriched the applicable scope of reactive raw materials. The prepared polycarboxylate superplasticizer showed good cement paste fluidity and fluidity retention, which manifested as good adaptability to cement and application performance in concrete.
Abstract:
A regulating cementitious material for promoting hydration of Portland cement is provided. The regulating cementitious material may include ingredients by weight as follows: ye'elimite, 27˜68 parts; anhydrite, 29˜68 parts; lithium nitrite, 2˜5 parts; ethylene glycol monoisopropanolamine, 0.14˜0.29 parts; triethanolamine acetate, 0.04˜0.09 parts; and polyglycerol, 0.04˜0.09 parts. An early strength of Portland cement can be improved through a cooperative hydration between minerals and an enhanced solubilization of a complexing agent.
Abstract:
Synthesis and application of an alcohol amine with an extended main carbon chain are provided, belonging to the field of chemical building materials. Under the action of a catalyst, tertiary amine is subjected to a two-step substitution reaction, a hydrolytic reaction and a reducing reaction to obtain a novel alcohol amine (NAA). The novel alcohol amine as provided may have a better grinding aid effect than triethanolamine while is added into cement as a cement grinding aid, and thus has a wide application prospect.