197results about How to "Increase the degree of branching" patented technology

The invention discloses a domino catalyzing system of a primary metallocene catalyst, which takes ethane as a sole monomer to prepare branched polyethylene, and the application thereof, which relates to vinyl copolymer. the catalyzing system is a compound catalyzing system consisting of the single primary metallocene catalyst and two different catalyst promoters, wherein, the primary catalyst is a metallocene catalyst with a structural formula of Cp<1>MR<1>R<2>R<3>, Cp<1>Cp<2>MR<1>R<2> or Cp<1>-D-Cp<2>MR<1>R<2>; alkyl aluminium acts as an oligomerization catalyst promoter; methylaluminoxane or triisobutyl aluminium or triethyl aluminum that is not used together with the oligomerization catalyst promoter acts as a copolymerization catalyst promoter; the mole ratio between the oligomerization catalyst promoter and the primary catalyst is 10-1000 to 1, and the mole ratio between the copolymerization catalyst promoter and the primary catalyst is 20-1000 to 1. The catalytic activity of the metallocene domino catalyzing system for preparing the branched polyethylene is 5 multiplied by 10<5> to 5 multiplied by 10<7>gPE/(molM per hour), the degree of branching is 10-200/1000C, the molecular weight of the branched polyethylene prepared under the effect of the catalyzing system ranges from 1 multiplied by 10<5> to 4 multiplied by 10<5> and the melting point is below 120 DEG C or even no melting point exists.

The invention relates to a preparation method of a monodispersed vaterite type calcium carbonate microsphere, which comprises the following steps of: (1) preparing a calcium salt aqueous solution with the concentration of 30-150mmol/L, and then, adjusting the pH value of the calcium salt aqueous solution to 8.5-10; (2) preparing a carbonate or hydrocarbonate aqueous solution with the concentration of 30-150mmol/L, and then, adjusting the pH value of the carbonate or hydrocarbonate aqueous solution to 8.5-10; (3) preparing a functional hyperbranched polyglycerol aqueous solution with the concentration of 20-400mg/L, and then, adjusting the pH value of the functional hyperbranched polyglycerol aqueous solution to 8.5-10; (4) mixing and uniformly stirring the carbonate or hydrocarbonate aqueous solution, the calcium salt aqueous solution and the functional hyperbranched polyglycerol aqueous solution at the temperature of 10-35 DEG C, and aging for 1-12h; and (5) centrifuging or filtering the mixed solution, cleaning a sediment, and drying to obtain the monodispersed vaterite type calcium carbonate microsphere. The monodispersed vaterite type calcium carbonate microsphere prepared by using the preparation method provided by the invention has the advantages of uniform particle size, stable crystal form and industrial application value.

The invention discloses a novel late transition metal alpha-diimine nickel (II) olefin polymerization catalyst with a symmetrical structure. The catalyst is a didentate coordination compound formed by an alpha-diimine ligand with a symmetrical Schiff base structure and a halogenide of later transition metal nickel (II). In the presence of diethyl aluminium chloride (DEAC) used as a cocatalyst, the coordination compound catalyst of nickel has higher activity for catalyzing ethylene to polymerize, which can reach 107gPE/(mol Ni h Bar), and obtained polyethylene has higher degree of branching, which can reach 114 branched chains per 1,000C.

The invention discloses a reinforcing agent of amphoteric polyacrylamide cardboard paper. In the existing reinforcing agents, some have unobvious reinforcing effect, and some have extremely great pollution and damage to the environment. The reinforcing agent is prepared by deionized water, anion monomer, cation monomer, non-ion monomer, pH adjusting agent and an initiating system, and is characterized in that: the anion monomer selects the mixture of carboxylic group unsaturated monomer and sulfonic group unsaturated monomer for use; and the non-ion monomer selects the mixture of acrylamide or acrylamide derivative and methyl methacrylate or methyl methacrylate derivative for use. The reinforcing agent has favorable reinforcing effect and greatly improves the safety and environment protection of production.

The invention discloses a highly branched oily alkane polymer, and a preparation method and application thereof. The highly branched oily alkane polymer provided by the invention has the following characteristics that (a) the viscosity index ranges from 100 to 300, (b) the pour point ranges from minus 50 DEG C to minus 10 DEG C, (c) the molecular weight ranges from 300 to 500,000 g/mol, and (d) the number of methyls corresponding to every 1000 methylenes ranges from 100 to 500. The invention also discloses a preparation method and application of the highly branched oily alkane polymer, and a lubricating oil prepared from the highly branched oily alkane polymer. The highly branched oily alkane polymer provided by the invention is high in viscosity index and high in branching degree, and thus can be used as a base oil or a processing assistant for an advanced lubricating oil.

A molecular sieve comprising a core having deposited thereon a surface layer, wherein the core is a zeolite containing silicon and at least one element selected from gallium and iron and the surface layer has a higher Si:Al ratio than that of the silicon:selected element ratio of the core, provides for lower branching in olefin oligomerization products.

The invention relates to the field of preparation methods of polyetheramine, and especially relates to a hyperbranched polythioether polyamine, and a preparation method and a use thereof. The preparation method is simple, raw materials are nontoxic and are easy to obtain, cysteamine hydrochloride can be prepared through hydrolyzing human and animal hair, alkynyl glycidyl ether can be directly purchased, and the method also has the advantages of low requirements of devices involved in the preparation process, no special or strict conditions, and mild reaction conditions. The molecular periphery of the hyperbranched polythioether polyamine has a plurality of primary amino groups, so the hyperbranched polythioether polyamine can be used as an epoxy resin flexible curing agent; and hyperbranched polythioether polyamine hydrochloride which is the precursor of the hyperbranched polythioether polyamine has a strong fluorescence effect, a good antibacterial performance and a good sterilizing performance.

The invention provides a polylactic acid segmented copolymer and modified polylactic acid preparation method. The method includes: reacting branched polyactic acid with halogenated acid halide to obtain macroinitiator to further react with glycidyl methacrylate to obtain the polylactic acid segmented copolymer; and finally, blending the branched polyactic acid, the polylactic acid segmented copolymer and polylactic acid to obtain the modified polylactic acid. Compared with the prior art which using bis-glycidyl ester for modifying the polylactic acid, the method has the advantages that firstly, the polylactic acid-polyglycidyl methacrylate segmented copolymer is a macromolecular compound and can be in cross-linking reaction with the branched polylactic acid and the polylactic acid to form polymer with higher molecular weight and higher branching degree, so that the problems of proneness to migration and osmosis of micromolecular branched cross-linking agent are solved, and stability of the modified polylactic acid is improved; and secondly, the polylactic acid-polyglycidyl methacrylate segmented copolymer with an intrinsic branched polylactic acid structure unit has high compatibility to the branched polylactic acid and the polylactic acid.

The invention relates to single-component water-based black paint for an automobile and a preparation method thereof. The single-component water-based black paint for the automobile is prepared by mixing three components A, B and C according to the weight ratio of 4 to (4 to 7) to (0.05 to 0.2), wherein the component A is prepared from the following components in parts by weight: 3 to 7.5 parts ofhigh-pigment carbon black, 15 to 35 parts of water, 3 to 10 parts of methyl ethylene glycol, 0.3 to 2.5 parts of base material wetting agent and 1.5 to 7.5 percent of dispersant; the component B is an aliphatic polyurethane dispersion body; the component C is a rheological agent. According to the single-component water-based black paint for the automobile, the compatibility problem of raw materials is remarkably improved, and the flowability, storage stability, luster, blackness and a blue phase are improved.

Novel late-transition-metal alpha-diimine nickel (II) complexes containing p-benzhydryl substitutes are disclosed. According to the complexes, two bulky groups which are benzhydryl are introduced to the para positions of imine nitrogen atoms on aromatic rings, and therefore ethylene insertion is accelerated, catalyst activity is improved, the transferring rate of active chains to a monomer is reduced, and a polymer having a high molecular weight is prepared. Under activation by a cocatalyst that is diethylaluminium chloride, a catalytic system catalyzing ethylene polymerization has high catalytic activity (can be 10<6> g PE/(mol Ni h)), and prepared polyethylene having a high molecular weight has a high degree of branching (can be 131 branches per 1000 C). Because of ortho-position small-steric-hindrance substitution and immobilization by para-position bulky benzhydryl, 2-hexene can be easily inserted to a metal center, and therefore chain shuttling polymerization of the 2-hexene has ahigh conversion ratio (88%), and a branch polymer having a high molecular weight and a low degree of dispersion is obtained. Accordingly, the catalyst has good potential application value in industrial polyolefin production.

The present invention relates to high pressure polymerization reaction process catalyzed with the mixture of two kinds of post-transition metal catalyst to prepare polyethylene with double molecular weight distribution peaks. These two kinds of catalyst are mixed in different ratio and are acted with co-catalyst modified methyl aluminoxane to catalyze the ethylene polymerization in single high pressure reaction kettle, so as to obtain blended polyethylene with double peak molecular weight distribution through one-step reaction. The produced blended polyethylene includes high molecular weight component with high branching degree and low molecular weight component with linear structure and greatly improved mechanical performance and machining performance.

The invention relates to a polypropylene material with a low linear expansion coefficient and a preparation method of the polypropylene material. The polypropylene material with the low linear expansion coefficient is prepared from the following raw materials: polypropylene resin, a functional ethylene-octylene copolymer, a compatilizer, talcum powder, flat glass fiber, an antioxidant and a weather resistant agent. By adjusting components and proportions of the raw materials, the polypropylene material has the low linear expansion coefficient and good mechanical properties, and can be appliedto automobile bumpers, apron boards and the like.

The invention provides polyester resin capable of rapidly cured at low temperature and a preparation method thereof. The polyester resin is prepared from the following raw materials in parts by weight: 6.5-9.5 parts of polyalcohol, 13.5-14.5 parts of acid, 0.015-0.025 part of an esterification catalyst and 0.2-0.3 part of a curing accelerant. Compared with the prior art, according to the polyesterresin capable of rapidly cured at low temperature, high-activity monomers are combined, so that the finally prepared polyester resin is high in activity; softening point of the polyester resin is slightly reduced; a powder paint prepared by the polyester resin can be fully cured in short time under the low-temperature condition; the energy consumption is greatly reduced; in addition, good low-temperature leveling property and storage stability of the powder paint can also be ensured; meanwhile, the powder paint has excellent curing property and film formation property.

The invention discloses a high-melt-strength high-bonding-property thermoplastic elastomer and a preparation method thereof. The high-melt-strength high-bonding-property thermoplastic elastomer contains the following components in parts by weight: 25-35 parts of a high molecular weight styrene copolymer, 20-30 parts of polypropylene, 6-14 parts of thermoplastic polyurethane, 5-12 parts of a chain extender, 3-8 parts of a tackifier 1, 2-9 parts of a tackifier 2, 14-20 parts of tackifier filling oil, 3-14 parts of a compatilizer and 2-6 parts of an antioxidant. The preparation method comprises the following steps: weighing the materials in the formula in parts by weight; uniformly mixing the materials; inputting the mixed raw materials into a feeding hopper of a twin-screw extruder; and performing melt extrusion and granulation. The thermoplastic elastomer disclosed by the invention is high in melt strength, good in mechanical strength, difficult to shrink and good in encapsulating adhesive property, and is suitable for the fields of toy tires, bathroom hoses and automobile sealing strips, etc.

The invention discloses a preparation method of high-performance starch slurry. The preparation method comprises the steps of dispersing starch with the mass concentration of 10-40% into water; stirring and heating to 40-60 DEG C; reacting for 3-8 hours through stirring a starch branching enzyme at the constant temperature of 40-60 DEG C, wherein 30-150U/g starch is added into the starch branching enzyme; and filtering, centrifugally dehydrating and drying to obtain modified high-performance starch slurry with high branching degree. Compared with unmodified starch, the high-performance starch slurry has the advantages that the gelatinization temperature is reduced, the slurry is not frozen at room temperature, the flowability is favorable, and the adhesion to a pulpified yarn is improved to a relatively high extent.

The invention relates to a functional emulsion styrene-butadiene rubber, characterized in that: the number-average molecular weight is 3*10<4>-35*10<4>, based on 100% of total monomer, the sum of the weight percentages of bound styrene and styrene derivative is 10-50%, and the weight percentage of butadiene is 50-90%; based on 100% of the sum of the weight percentages of bound styrene and styrene derivative, the weight percentage of bound styrene is X%, and the weight percentage of styrene derivative is (100-X)%, wherein the X is no less than 0 and less than 100; the styrene derivative is selected from styrene containing nitrogen atom substituent, and at least contains one tertiary amine group substituent.

The invention discloses recoat-able polishing-free unsaturated polyester resin for piano lacquer and a preparation method of the unsaturated polyester resin. The unsaturated polyester resin comprises the following components in percentage by weight: 15 to 25 percent of an air-dry monomer, 25 to 35 percent of polyatomic acid, 20 to 30 percent of polyhydric alcohols, 20 to 30 percent of a solvent, 0.05 to 0.1 percent of an antioxidant and 0.01 to 0.05 percent of a polymerization inhibitor. The preparation method comprises the following steps: adding the polyatomic acid, the polyhydric alcohols, the solvent and the polymerization inhibitor into a reaction kettle in sequence, switching on stirring and heating at the same time, heating to 180 to 200 DEG C, and preserving the heat; continuously detecting an acidity value, cooling to 120 DEG C when the acidity value is reduced to 120 to 130mgKOH/g, then cooling to 120 DEG C and adding the air-dry monomer, uniformly heating to 200+/-5 DEG C by 3 hours, preserving the heat until the viscosity and the acidity value are qualified, then cooling and diluting the materials, performing filtration, and discharging a product. The piano lacquer prepared from the unsaturated polyester resin serving as a base material is high in surface hardness, and is higher in glossiness and transparency without polishing, construction period is short, the unsaturated polyester resin is recoat-able, convenient to prepare, and can be generally used in the bottom surface, and the production efficiency is greatly improved.