39 results about "Zirconocene dichloride" patented technology

The invention relates to a preparation method of silicon carbide/zirconium carbide composite ceramic, and relates to inorganic nonmetal material composite ceramic. The preparation method comprises the steps of: dissolving bis(cyclopentadienyl) zirconium dichloride with a solvent under the protection of inert atmosphere, and adding liquid hyperbranched polycarbosilane to obtain a mixture A; and distilling the mixture A under reduced pressure under the protection of inert atmosphere to remove the solvent, and carrying out cracking reaction in inert atmosphere to obtain the silicon carbide/zirconium carbide composite ceramic. According to the invention, bis(cyclopentadienyl) zirconium dichloride is used as a zirconium source, and is used for catalyzing the crosslinking reaction of liquid hyperbranched polycarbosilane, so as to increase ceramic yield; zirconium carbide can inhibit the growth of silicon carbide microcrystal grains, and improve high-temperature resistance and oxidation resistance of the composite material; the zirconium content in the composite ceramic can be controlled by controlling the content of bis(cyclopentadienyl) zirconium dichloride in a hybrid precursor; the liquid hyperbranched polycarbosilane/bis(cyclopentadienyl) zirconium dichloride hybrid precursor is free of oxygen, thus the gas escaped in the high-temperature cracking process is reduced; the ceramic has high compactness; and the preparation method is simple to operate, and is easy for engineering.

The method of promoting olefin polymerization uses a nanoparticle filler to increase the activity of a metallocene catalyst for in situ polymerization of polyolefins. The filler may be nanoparticles of manganese, or nanoparticles of manganese-doped titanium dioxide. The method includes the steps of (a) mixing a metallocene catalyst, e.g., zirconocene dichloride, with nanoparticles of the filler in an organic solvent, e.g., toluene, in a reactor to form a reaction mixture; (b) immersing the reactor in a temperature bath for a period of time sufficient to bring the mixture to an optimal polymerization reaction temperature; (c) adding monomer to the mixture in the reactor; (d) adding methylaluminoxane (MAO) as a co-catalyst to the reaction mixture to initiate polymerization; and (e) quenching the polymerization, e.g., by adding methanol containing 5% hydrochloric acid by volume to the reactor.

The invention relates to a light-sensitive Zr-B-Si-C ceramic precursor and an in-situ preparation method thereof. The method comprises the following steps: uniformly mixing methylvinyldichlorosilane and a borane dimethyl sulfide complex, and then adding metal sodium for dechlorination to obtain methylvinyl borosilane; uniformly mixing chloromethyltrichlorosilane, methylchloromethyldichlorosilane and bis(cyclopentadienyl)zirconium dichloride, then adding metal magnesium to carry out a first heat preservation reaction, and then adding a reducing agent to carry out a second heat preservation reaction to obtain polyzirconocarbosilane; uniformly mixing methylvinyl borosilane and polyzirconocarbosilane to obtain vinyl Zr-B-Si-C alkane; and uniformly mixing the vinyl Zr-B-Si-C alkane with mercaptopropionate, and then adding a photoinitiator to initiate a polymerization reaction to prepare the ceramic precursor. The problems of high viscosity, high thermal stress, structural member mechanicalproperty attenuation and the like of a traditional photocuring system are solved, and a high-quality raw material is provided for photocuring 3D printing of an ultrahigh-temperature ceramic structuralmember.

The invention discloses a load-type metallocene catalyst for olefin polymerization and a preparation method thereof. The preparation method comprises the following steps: performing silicon tetrachloride modification on the surface of an activated silica gel carrier, and performing bis-cyclopentadienyl-zirconium dichloride in-situ synthesis on the surface of the silicon tetrachloride modified silica gel to obtain the product, wherein the catalyst is a solid granule with the particle size distribution scope of 20-30 microns, the structure is stable when the environment temperature is under 300 DEG C, the surface metallocene modification rate is 45.7-47.3%, and the zirconium element content on the surface of the catalyst is 0.093-0.095 mmol/g. When the catalyst and the cocatalyst methylaluminoxane are compounded for catalyzing the homopolymerization of the olefin, the catalytic activity of the catalyst is higher than that of the catalyst obtained by loading zirconocene dichloride with the silica gel under the existence of methylaluminoxane, and the obtained polymerizate is white without caking. When the catalyst and the cocatalyst are compounded for the catalysis of the olefin homopolymerization, the catalytic activity of the catalyst is high and the obtained polymerizate product is white without caking.

The invention discloses a method for preparing quinoline compounds under catalysis of zirconocene dichloride. According to the method, 3-butyne-2-one compounds and an o-aminophenylmercaptan compound are taken as raw materials, zirconium dichloride is taken as a catalyst, L-phenylalanine, tyrosine and the like are taken as catalyst ligands, and N,N-dimethylformamide is used as a solvent, and elemental iodine, hydrogen peroxide, peroxy tert-butyl alcohol and the like are used as oxidizing agents, so that the quinoline compound can be prepared in a high-efficiency and high-yield manner. The catalyst used in the method is less in use amount, low in cost and stable in air, reaction conditions are mild, and operation is simple. After the reaction is finished, the product is extracted and washed,simple column chromatography separation is carried out, and then the quinoline compound can be obtained. The method provides a low-cost efficient way for preparation of the quinoline compound and hasa wide application prospect.

The invention relates to a method for synthesizing zirconocene dichloride, which comprises the following process steps: depolymerizing cyclopentadiene: depolymerizing the cyclopentadiene under inert atmosphere, and collecting cyclopentadiene monomers obtained by distillation for standby; heating a solvent of diglycol ether and sodium wires under the inert atmosphere, then dripping the cyclopentadiene monomers, and obtaining diglycol ether solution of cyclopentadienyl sodium; dripping the well prepared cyclopentadienyl sodium solution into alkane suspension of zirconium tetrachloride solids, and carrying out reaction at the temperature of 15-35 DEG C; removing alkane under one atmospheric pressure, further removing the diglycol ether, obtaining dark gray solids, carrying out extraction on the solids by using a Soxhlet extractor, filtrating extraction solution, depressurizing, removing the solvent by evaporation, cooling, then precipitating the solids, and obtaining a target product. The method for synthesizing the cyclopentadienyl sodium changes the reaction solvent and the reaction temperature, so that the sodium wires can be melted, thereby forming sodium sand to be evenly distributed in the solvent; meanwhile, the high temperature can also depolymerize the partial polymerized cyclopentadiene, basically quantitatively carry out the reaction and improve the reaction yield.

The invention relates to the technical field of preparation of halogen-free flame retardants, and discloses an anti-static polyethylene glycol monooleate halogen-free flame retardant. The anti-staticpolyethylene glycol monooleate halogen-free flame retardant includes the following experiment raw materials of polyethylene glycol monooleate, an antioxidant complex, an organosilicon flame retardantauxiliary and a synergistic metallic and non-metallic catalyst, and the polyethylene glycol monooleate is a polymer of oleic acid and polyethylene glycol. According to the anti-static polyethylene glycol monooleate halogen-free flame retardant, the synergistic metallic and non-metallic catalyst is a complex of zirconocene dichloride and N-bromosuccinimide, through the zirconocene dichloride, the small amount of polyethylene glycol monooleate is coordinated to form a polyglyoxal monooleate compound, under catalysis of N-chlorosuccinimide, the polyglyoxal monooleate compound is chloridized intopolyoxalyl chloride monooleate, a cross-linking belt is formed between the polyethylene glycol monooleate polymer by the polyoxalyl chloride monooleate, and thus the polyethylene glycol monooleate polymer has stable conductive performance.

Linear low density polyethylenes (LLDPEs) that have relatively high melt index ratios (MIR) and relatively high melt strength (MS) are described. This combination of melt properties is achieved by a substantially non-blended LLDPE. Catalysts used to produce these polyethylenes are generally a blend of bridged bisindenyl zirconocene dichlorides, where one zirconocene contains saturated indenyls and the other unsaturated indenyls.

The invention discloses a method for preparing 1,5-benzothiazine compounds under the catalysis action of zirconocene dichloride. According to the method, 3-butyne-2-ketone compounds and o-aminobenzenethiol compounds are taken as raw materials, zirconocene dichloride is taken as a catalyst, and the 1,5-benzothiazine compounds are prepared efficient in a high-yield manner under the promotion actionof ligands such as L-phenylalanine, 3-nitrophthalic acid, 2-aminobenzene sulfonic acid and the like. According to the method, a few catalyst is used and is low in cost, non-toxic and stable to the air, the reaction conditions are mild, short time is consumed, operation is simple, the atom economy is high, all that is required is to perform simple column chromatography isolation on a product afterthe reaction ends, and the 1,5-benzothiazine compounds can be obtained. A novel, low-cost and efficient way is developed for preparation of the 1,5-benzothiazine compounds, and the method has broad application prospects.