39results about How to "Moderate molecular weight distribution" patented technology

A solid catalyst component for olefin polymerization includes titanium, magnesium, a halogen, and a compound represented by the following formula (1): R1O—C(═O)—O—Z—OR2, and an olefin polymerization catalyst includes the solid catalyst component, an organoaluminum compound, and an optional external electron donor compound. An olefin polymer that has a moderate molecular weight distribution while maintaining high stereoregularity can be produced by utilizing the solid catalyst component and the olefin polymerization catalyst.

The invention discloses a production method and production equipment for special materials for high-grade polypropylene melt-blown non-woven fabrics. For every 100 kilograms of polypropylene, 50-200 grams of long-acting stabilizers and 25-200 grams of short-acting stabilizers are added to achieve high temperature resistance and stability. 25-160 grams of lubricant, 20-100 grams of lubricant; the mixer stirs, feeds to the extruder, and reacts in the screw reaction section of the twin-screw extruder; the production equipment, including the mixer, mixes uniform raw materials from mixing The material outlet goes down to the middle silo, and the bottom outlet of the middle silo is connected to the inlet of the extruder. The extruder has a twin-screw structure. The extruder sends the processed material to the cooling water tank through the inclined water tank for cooling, and then in the air dryer Air-dried, granulated in a granulator, screened by a vibrating sieve, and sent to a homogenizing blending tank through a rotary feeder. The invention has the beneficial effects of mixing evenly, solving the molding problem of high-fluidity melt index polypropylene, and being suitable for conventional production.

The invention discloses a high slump retarding polycarboxylate water reducer and its preparation method and application. The water reducer is prepared from the following raw materials in molar parts: 10-30 parts of small molecule unsaturated carboxylic acid, 3‑8 parts of esters of small molecular unsaturated carboxylic acids, 1‑5 parts of salts of small molecular unsaturated carboxylic acids, 2‑6 parts of polyethylene glycol diacrylate, 1‑5 parts of unsaturated polyether macromonomers , 8-20 parts of acrylamide monomer, initiator and chain transfer agent; wherein said acrylamide monomer is acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), 2 ‑acrylamido‑2‑phenylethanesulfonic acid (AMSS) is a group of three monomers. The molecular structure of the superplasticizer is designed according to the ease and slump retention of the construction requirements, and finally a high-slump retention and retardation polycarboxylate superplasticizer with excellent comprehensive performance is obtained. In construction, a low dosage can achieve a higher water reducer The water rate can ensure the construction, and the slump retention is excellent, and the slump is basically not lost within 3 hours, and it has wide applicability in concrete construction.

The invention discloses a double-screw extruder suitable for melt-blown nonwoven cloth special material production. The double-screw extruder comprises a cylinder, wherein the cylinder is arranged transversely on a bracket; an exhaust chamber and a degradation agent injection hole are arranged above the cylinder; a heating tile is further packaged on the surface of the cylinder; one end of the cylinder is connected with a blanking barrel; double screws are arranged in the cylinder; the length-diameter ratio of the double screws is 40-58; and screw elements sleeve the double screws. The double-screw extruder has the following beneficial effects: by utilizing the length-diameter ratio of the screws, the screw combination design and the degradation agent feed hole position design, the raw materials and auxiliary materials are mixed completely and uniformly during reaction, the reaction is relatively sufficient, the product melt index is stable, the molecular weight distribution is proper, and the double-screw extruder is suitable for a melt-blown spinning process.

The invention discloses a method based on autocatalysis self-initiation ring opening of a poly(N-heterocylic carbene) structure to synthesize a brush polymer. The method includes: under inert gas shielding, adding annular monomer capable of being in ring opening polymerization under catalytic action of N-heterocylic carbene into an organic solution containing poly(N-heterocylic carbene), wherein a molar ratio of poly(N-heterocylic carbene) repetitive unit to at least one annular monomer is 1:1-1000, reaction temperature is minus 80 DEG C-120 DEG C, and reaction time is 10s-48h. The invention further discloses the brush polymer of a poly(N-heterocylic carbene) carbon dioxide adduct structure obtained by adding carbon dioxide to terminate reaction in the method. More brush polymers various in structure can be obtained by repeating the method. The method is simple in step, an initiator is not needed, a catalyst is metal-free, and the obtained polymer is narrow in molecular weight distribution, controllable in structure, high in grafting density and wide in application range.

The present invention relates to a synthesis method of a bimodal-distribution ethylene-alpha-alkene-non-conjugated dialkene random copolymer. The method comprises the following steps: a high-molecular weight part ethylene-propylene copolymer is synthesized from ethylene, propylene and hydrogen (the mol ratio is 1:1.0-3.0:0.15-0.30) and ethidene norbornylene 2-5 mL / L hexane; a low-molecular weight part ethylene-propylene copolymer is synthesized from the ethylene, the propylene and the hydrogen (the mol ratio is 1:3.0-4.5:0.9-2.0) and ethidene norbornylene 8-12 mL / L hexane; the main catalyst is soluble vanadium complex, and the cocatalyst is ethylaluminium sesquichloride; the mol ratio of Al to V is 1-100; the activating agent for the low-molecular weight part is ethyl trichloroacetate; and the mass ratio of the high-molecular weight part ethylene-propylene copolymer to the low-molecular weight part ethylene-propylene copolymer is 80 / 20-40 / 60. The copolymer has the advantages of high Mooney viscosity and moderate molecular weight distribution, and can be used for processing rubber for automobile gland strips.

The invention discloses an amido-bridged bisaryloxy rare-earth metal guanidyl compound. The amido-bridged bisaryloxy rare-earth metal guanidyl compound is characterized in that the general formula of the compound is [ONNO]Ln[(R1N)2C(NR2)], and the chemical structural formula of the compound is defined in the specification, wherein Ln is one of rare-earth metals ytterbium, yttrium and samarium; [ONNO]=Me2NCH2CH2N[CH2-(2-O-C6H2-R2-3-R3-5)]2, R2 and R3 are selected from one of methyl, tertiary butyl and cumenyl; and [(R1N)2C(NR2)] represents guanidyl, R1 is selected from one of isopropyl and cyclohexyl, and NR2 is selected from one of diphenylamine group, diisopropylamine group, di(trimethylsilyl) amine group, di(dimethylsilyl) amine group and piperidyl group. The compound is simple in synthesis, clear in structure and high in yield. The invention provides a preparation method for the compound aforementioned and an application method for catalyzing the ring opening polymerization of 1,4-dioxane-2-ketone by using the compound as a catalyst simultaneously. The preparation method is moderate in conditions, fast in reaction speed and high in activity; and the obtained polymer is high in molecular weight and proper in molecular weight distribution.