33results about How to "Strong steric hindrance effect" patented technology

The invention discloses a preparation method of an insulating medium for improving energy storage density, which comprises dissolving 1,4-phenylene diisothiocyanate in a polar solvent, adding organic diamine, and reacting in a nitrogen environment and room temperature 3-6 hours, then add 4,4'-diaminodiphenyl ether and pyromellitic dianhydride, and react for 12-18 hours under nitrogen environment and room temperature to obtain random copolymerization of polythiourea and polyamic acid The compound solution; the random copolymer solution of polythiourea and polyamic acid is spread on a copper plate, and the temperature is raised by gradient to obtain a random copolymer of polythiourea and polyimide. The invention controls the dielectric constant and breakdown field strength by changing the arrangement of polyimide monomers in the copolymer molecular chain, thereby changing the dielectric response characteristics and trap parameters of the material, and finally controlling or improving the energy storage of the material Density, can be widely used in high-voltage energy storage equipment, pulse power sources, aerospace, hybrid vehicles and other fields.

The invention relates to an ultra-dispersion agent for filling modification of polymer materials and a preparation method thereof, which belong to the technical fields of new materials and the chemical industry. The preparation method comprises the synthesis of an active solvent chain segment and the graft polymerization of an anchor group. The technology for the synthesis of the active solvent chain segment comprises the following steps of: mixing acrylic ester, styrene and a cyclohexane monomer, adding a corresponding regulator and an initiator, and taking liquid paraffin as a reaction medium; adding all the materials into a reactor which is pre-filled with the liquid paraffin; and controlling the temperature, the stirring speed and the reaction time in the reactor, discharging the materials when the conversion rate is measured to achieve 95%, and preparing the active solvent chain segment. The technology for the graft polymerization of the anchor group comprises the following stepsof: adding the prepared active solvent chain segment into the reactor, gradually dripping the mixture of a silane monomer, the initiator and the regulator into the reactor and controlling the temperature, the stirring speed and the reaction time till that a system generates yellow solids. The ultra-dispersion agent can be used for the filling modification of the polymer materials.

The invention relates to a preparation method of a modified natural chitin bio-based high-performance polycarboxylate superplasticizer. A chitin high polymer is used as a raw material for preparing the polycarboxylate superplasticizer. The chitin high polymer is subjected to deacylation and degradation treatment to obtain a modified chitin oligomer connected with a hydrophilic methylol group and an amino group; maleic anhydride containing a double bond is introduced onto the amino group of the modified chitin oligomer by a grafting reaction; N-maleic anhydride-oligomeric chitin graft and sodium methacrylate sulfonate are subjected to copolymerization to prepare a novel high-performance polycarboxylate superplasticizer containing -SO3H, -COOH, -OH, -CH2OH groups. The prepared polycarboxylate superplasticizer has a good dispersion effect on cement particles at a lower dosage, has a certain comb structure, can be adsorbed on the surface of the cement particles, and can generate a steric-hinerance effect. Then, concrete doped with the polycarboxylate superplasticizer has excellent fluidity retention property.

The invention discloses a polycarboxylate-type macromolecular water reducer and a preparation method thereof, and belongs to the field of concrete additives. With methoxypolyethylene glycol ester macromonomers, allyl polyoxyethylene ether and amide monomers as raw materials, the polycarboxylate-type macromolecular water reducer is synthesized through a macromonomer direct copolycondensation method; the synergistic effect of multiple organic functional groups is effectively achieved, the defects of an existing water reducer product are overcome, the water reducing rate is increased, and the slump retaining property and the compressive strength are improved. According to the polycarboxylate-type macromolecular water reducer and the preparation method thereof, the production process is simple, the reaction conditions are easy to control, the production equipment requirement is low, and industrial application and popularization are easy.

The invention discloses an aminated intermediate, and aminated polyether and phosphorylated star-like products, a preparation method and application thereof. The aminated intermediate is characterizedin that the aminated intermediate and the chlorinated polyether are subjected to amination reaction, so as to obtain the aminated polyether; the aminated polyether intermediate, phosphorous acid, a catalyst and aldehyde monomers are subjected to phosphorylation reaction, so as to obtain the star-like product containing phosphorous acid groups; the star-like product containing the phosphorous acidgroups can be used as a cement dispersant, and the better dispersing effect is realized.

The invention provides a polycarboxylic acid concrete plasticizer which is formed by copolymerization of three monomers A, B and C and is a polymer with the weight-average molecular weight of 15000-40000, wherein the three monomers are as follows by weight percent: monomer A is 60-70%, monomer B is 20-30% and monomer C is 5-10%; the structure of the monomer A is shown by the following formula, wherein R1 is alkyl group with less than or equal to five carbon atoms or hydrogen atom; m and n are integers within the range of 0-5; A, B, C, D , E, G, H, J and K are respectively integers within the range of 0-30, but not simultaneously 0; the monomer B is the mixture of more than two of acrylic acid, methacrylic acid, maleic acid, maleic anhydride or maleic anhydride salt; and the monomer C is the mixture of more than two of sodium methyl acryl sulfonate, sodium vinylsulphonate, styrene sodium sulfonate or 2-acrylic amide-2-methyl acrylic acid. The concrete plasticizer has the characteristics of good compatibility with various cements, and high water reducing rate and anti-collapse performance. The invention also provides a preparation method of the plasticizer.

The invention discloses a water-reducing agent composition for coal mine paste filling, a preparation method and application thereof. The components of the water-reducing agent composition are proportioned by mass fraction as follows: aliphatic high-efficiency water-reducing agent 45%~ 55%, reinforcing agent 2%-10%, dispersant 0.2%-0.7%, water-retaining agent 0.005%-0.02%, and the balance is water. The aliphatic high-efficiency water-reducing agent in the water-reducing agent composition has a synergistic effect with the reinforcing agent, which can improve the early strength of the gangue body filling material, and the dispersing agent can stabilize the dispersion and suspension of particles, and promote the aliphatic high-efficiency water-reducing agent. The water-retaining agent can improve the packing performance of the filling material slurry, and the combined action of each component can be used to improve the flow performance of the gangue gypsum filling material, improve the packing performance of the gangue gypsum filling material, and at the same time improve the gangue gypsum filling material. The strength of the filling material can reduce the cost of the filling material, and can effectively control the slump of the paste filling material, so as to meet the pumping performance of long-distance transportation in coal mines.

The invention discloses a mud-resistant sodium alginate side chain comb-shaped polycarboxylate water reducer and a preparation method thereof. The raw materials for preparing the water reducer include: side chain macromonomer isopentenyl polyoxyethylene ether (TPEG2400) , main chain small monomer acrylic acid, chain transfer agent sodium methacrylate, chain initiator ammonium persulfate, sodium alginate and various parts of water. Acrylamide with a double bond was introduced on sodium alginate in advance by using the Uggi reaction. Secondly, use the aqueous solution free radical polymerization method to polymerize with each monomer, use the water retention effect of the hydrophilic group on the molecular structure of sodium alginate, and the spatial conformation of the long chain molecule of sodium alginate to synthesize the anti-mud comb modified by sodium alginate Shaped polycarboxylate superplasticizer. In cement slurry and concrete mixed with clay, it has excellent dispersibility and working performance, and reduces the sensitivity of polycarboxylate superplasticizer to clay. Promoting the application of natural polysaccharides in concrete additives is of great significance for the synthesis of green and environmentally friendly concrete admixtures.