30results about How to "Initiation temperature is low" patented technology

The invention discloses a method for preparing nitrogen and potassium contained superabsorbent resin from carboxymethyl potato residues. The method comprises the main process steps of enabling a potassium hydroxide solution and polymerization inhibitor removed acrylic acid to be subjected to neutralization reaction under the cooling of ice-water bath; adding the neutralized solution into a reaction vessel filled with carboxymethyl potato residues, acrylamide, potassium persulfate, sodium hydrogen sulfite, N, N'-methylenebisacrylamide and deionized water; stirring under the protection of nitrogen gas, heating in water bath, stopping stirring at the temperature of 25-45 DEG C, and preserving heat in boiling water bath for 1-2h; then, stopping introducing nitrogen gas, taking out a product, shearing the product into small blocks, drying the small blocks in a drying oven with the temperature of 40-60 DEG C until the weights of the small blocks are constant, and smashing to obtain the nitrogen and potassium contained superabsorbent resin prepared from carboxymethyl potato residues. Compared with the like product, the superabsorbent resin prepared by using the method disclosed by the invention is greatly improved in water absorbing capacity, low in preparation cost and favorable in application prospect on the aspects such as water retention of soil in drought regions, desert control, plant growth and the like.

The invention discloses a preparation method of polydimethyl diallyl ammonium chloride. It is based on the industrial cationic monomer DMDAAC aqueous solution obtained by a high-yield one-step clean preparation process as a raw material, adding persulfate as an initiator and Na4EDTA complexing agent at one time, controlling the reaction temperature under stirring, and controlling the initiation rate according to gradient temperature rise , initiate the polymerization reaction of monomer DMDAAC at a lower temperature, increase the degree of polymerization of the product PDMDAAC, improve the relative molecular weight, add an aqueous solution containing a small amount of initiator at a higher temperature in the later stage of the reaction to improve the monomer conversion rate in the product, and finally By controlling the amount of dilution water added, the solid content of the product is adjusted. The present invention is not only easy to obtain polymer products with higher relative molecular weight, but also has good economical and industrial bases for its preparation method; the initiation temperature is reduced, and the polymerization reaction is carried out under relatively mild conditions, which is easy to operate and low in production cost; PDMDAAC products with different solid contents and different uses can be obtained.

The invention relates to a high-adaptability multi-branched-chain amide imine type polycarboxylate based water reducer and a preparation method thereof, and belongs to the technical field of concreteadditives. The polycarboxylate based water reducer is composed of the following substances: polyether macromonomers, unsaturated acid monomers, branched-chain functional monomer methoxy polyethylene glycol mercaptoacetate, amide imine type functional monomer diethylenetriamine maleate, an initiator, a reducing agent and deionized water, wherein the molar ratio of the polyether macromonomers to theunsaturated acid monomers to the branched-chain monomers to the amide imine type monomers is 1:(2-5):(0.3-0.6):(0.5-1.0). The prepared water reducer has a relatively high water reducing rate and excellent slump retaining performance, and the problem of adaptability between cement concrete and the polycarboxylate based water reducer is also solved. The invention further provides a preparation method thereof. The preparation method comprises four steps, is scientific and reasonable, and is simple and feasible.

The invention relates to a synthesis method of acrylic ester copolymer with ultra-high molecular weight (more than 6 million). The technical problem to be solved by the invention is to provide a method with multistage reaction and higher efficiency. The method comprises the following steps: (1) preparation of a seed emulsion: adding a portion weight of water and two or more unsaturated monomers with olefinic bonds, wherein the weight ratio of water to the monomers is 1:0.6 to 1; adding an emulsifying agent and a pH buffer, and adding a portion weight of or the total weight of one or two oxidants and one or two reducers to carry out reaction completely, wherein the weight ratio of the oxidant to the reducer is 1:0.7 to 1.5; and (2) multistage polymerization reaction: adding unsaturated monomers with olefinic bonds in balancing amount in multiple stages after rising the temperature, keeping the temperature at 45 to 65 DEG C, adding the balancing amount of water in multiple stages, rising the temperature to 80 to 85 DEG C, and adding the balancing amount of the oxidant and the reducer.