143results about How to "The preparation process is safe and environmentally friendly" patented technology

The invention relates to a method for directly synthesizing a pure solid high-performance polycarboxylate water-reducer in one step, belonging to the field of water-reducers. According to the method, the pure solid high-performance polycarboxylate water-reducer is prepared by taking an acrylic compound and unsaturated polyoxyethylene ether as polymerization reaction monomers, adding a molecular weight regulator and carrying out free-radical polymerization reaction under the action of an initiator and under a solvent-free environment. The method disclosed by the invention is strong in controllability, high in polymerization degree, low in cost, environment-friendly and pollution-free, achieves the purpose of preparing the absolutely anhydrous pure solid polycarboxylate water-reducer by bulk polymerization, not only has the fluidity and holding property of cement paste, cement adaptability and concrete application performance which are similar to those of a polycarboxylate water-reducer prepared from a common solution by polymerization and can be prepared into any concentration of solution according to actual demands as the pure solid high-performance polycarboxylate water-reducer prepared by direct polymerization is an anhydrous pure solid, but also is free of postprocessing working procedures, such as heat drying or solvent separation and is more convenient to transport, saved in transport cost and favorable in market competitiveness and application prospect.

The invention relates to a preparation method for synthesizing a high-performance polycarboxylic acid water reducing agent by undergoing a one-step amidation reaction, belonging to the field of water reducing agents. In the invention, a high-performance polycarboxylic acid water reducing agent material is prepared by directly reacting with a one-step amidation method, i.e., the water reducing agent is obtained by undergoing an amidation reaction on reactants which are respectively polymethacrylic acid and methoxyl polyethenoxy ether containing amino at the other end under the action of a catalyst. The method has the advantages of conveniently-controlled process, easiness, practicability, low cost and environmental friendliness. An amide structure and a polyethenoxy ether structure are introduced into the molecular structure of the polycarboxylic acid water reducing agent by undergoing a one-step amidation reaction, so that high flow property of cement is realized, the flow property keeping ability and the cement adaptability are remarkably enhanced, and high flowability can be achieved under the conditions of low cement water factor and low mix proportion.