202results about How to "High Molecular Weight Distribution" patented technology

An alkylene and/or silylene bridged binuclear metallocene catalyst for styrene polymerization is represented by the following formula (I): where M1 and M2 are the same or different transition metal of Group IVb of the Periodic Table; Cp1 and Cp2 are the same or different cyclopentadienyl; alkyl, alkoxy, silyl or halogen substituted cyclopentadienyl; indenyl; alkyl, alkoxy, silyl or halogen substituted indenyl; fluorenyl; or alkyl, alkoxy, silyl or halogen substituted fluorenyl, which is capable of pi -electron, eta 5-bonding with M1 or M2; each of E1, E2 and E3, independently of one another, is a carbon atom or a silicon atom; m, p and q are integers of 0 to 15 and m+p+q>/=1; each of R1, R2, R3, R4, R5 and R6, independently of one another, is a hydrogen, an alkyl, an aryl, an alkoxy or a halogen; X is a hydrogen, an alkyl, an alkoxy or a halogen; and n is 3. M1 and M2 may also be in cardin form by mixture of (I) with a compound which abstructs an X gray from each metal atom and substitution then with non-coordinating anions.

The present invention relates to a binuclear metallocene compound, its preparation method and its application in olefinic polymerization. Said invention provides its structure expression formula, said compound can be matched with cocatalyst alkyl aluminoxane, and used for olefinic polymerization. It possesses high polymerization reaction activity, and can obtain olefinic polymerization product with high molecular weight and wide molecular weight distribution.

The invention provides a fluorine-containing polyimide optical waveguide material and the preparing method thereof relating to the integrating polymer material preparing method in optical device, which can be applied in waveguide optics device, the material is obtained from condensation and copolymerization of three monomers, that is the fluorine-containing polyimide is condensed and copolymerized from two diamine monomers and one dianlydride monomer or from two diamine monomers and one dianlydride monomer, after purification, the fluorine-containing polyimide n-methyl-2-pyrrolidone solution is obtained, and is then dropped on center of clean substrate for spin coating to form film, and desiccation and curing. The glass transition temperature of the material is above 200 DEG C, in the field of optical communication on 1550nm the optical loss is less than 0.6dB/cm, the refractive index on 1550nm is 1.5-1.6.

The present invention relates to a polymerization process for preparing syndiotactic polystyrenes, which comprises a step of microfluidizing in a microfluidization apparatus both a catalyst mixture consisting of a styrene monomer, a metallocene catalyst and an inert organic solvent and a cocatalyst mixture consisting of a styrene monomer, a cocatalyst and an inert organic solvent, and a step of reacting the microfluidized mixture with a catalyst and a cocatalyst in a reactor. The metallocene catalyst has a bridged structure of a complex of Group IV transition metals such as Ti, Zr, Hf etc. in the Periodic Table and a ligand having one or two cycloalkane dienyl groups such as cyclopentadienyl group, indenyl groups, fluorenyl group, and derivatives thereof. The reactor is a well stirred reactor equipped with agitating blades therein to mix the reactants well. In this invention, the plural number of reactors can be employed in series for more effective polymerization, and the plural number of microfluidization apparatuses can be employed in parallel.

The present invention relates to the field of olefin polymerization, particularly provides a catalyst for olefin polymerization, a preparation method and applications thereof. The catalyst for olefinpolymerization contains (i) a catalyst component, (ii) at least an alkyl aluminum compound and (iii) an external electron donor, wherein the catalyst component contains the product obtained by carrying out a reaction on a magnesium source, a titanium source and an internal electron donor, the internal electron donor contains a phosphate compound and a diether compound, the phosphorus content (calculated as the phosphorus element) in the catalyst component is not more than 0.06 wt% by using the total weight of the catalyst component as the reference, and the external electron donor has a structure represented by a formula (1). According to the present invention, the catalyst does not contain phthalate compounds (plasticizers), has high hydrogen response sensitivity and high stereospecificity, and can be used in olefin polymerization so as to obtain the polymer having narrow molecular weight distribution. The formulas (1) is (R17)x(R18)ySi(OR19)z.

The invention provides an organic chromium catalyst for ethylene polymerization and a preparation method thereof. The catalyst comprises a main active catalyst, an inorganic oxide carrier, a modifier and a cocatalyst, wherein the main active catalyst is a chromium salt, and the content of the main active catalyst in the catalyst is 0.01-5% by mass; technical requirements of the carrier inorganic oxide comprise that the surface area is about 200-700m<2>/g, the pore volume is about 1-4cc/g, the aperture is about 60-700 and the particle dimension is about 10-200mum; the modifier is a recovery liquid for the preparation of an alkylsilane chromate catalyst; and the cocatalyst is an alkyl compound of Al, Li, B and Zn. The organic chromium catalyst for the ethylene polymerization provided in theinvention has the advantages of high activity, proper induction time, and suitableness of the production of wide molecular weight distribution range polyethylene products; and the preparation method provided in the invention has the advantages of simple synthetic technology and low preparation cost.

The invention relates to a plastic radiating and ventilating water heater used in the field of heating and bath radiating and ventilating water heaters adopting hot water as a heat medium and relates to a method for making the radiating and ventilating water heater and a material thereof. The plastic radiating and ventilating water heater comprises an injection-molded structure or a molded sectional material and is characterized in that a coaxial heat exchanger is provided with heating medium channels and heated medium channels; a plurality of heat exchange pipes and a plurality of heated medium pipes are axially arranged in a sleeving way, the pipes with a bigger diameter are arranged outside the pipes with a smaller diameter in a sleeving way, and the heated medium pipes are arranged on the outermost layer; lock catch grooves of the heated medium channels and the heat exchange pipes, which are connected in series and communicated are fixedly connected with heat exchange abnormal pipes in a way of directly plugging in built-in lock catches and bonding under a heated condition, or in a way of directly plugging in the built-in lock catches and bonding with a glue solution, or in a way of direct-plug-in heated bonding and glue solution bonding; or the lock catch grooves and the abnormal heat exchange pipes are injection-molded into a whole by a die. The plastic radiating and ventilating water heater belongs to a novel radiating and ventilating water heater which can avoid oxidation or alkali corrosion problems, has excellent heat radiation and conduction properties and long service life, and can overcome the defect that the environment is worsened by the water quality of the heat medium.

The invention relates to a method for preparing a high-performance polyacrylonitrile solution for carbon fibers, and especially relates to a method for preparing the polyacrylonitrile solution through adopting a new initiator to mainly solve a problem of difficult process control caused by wide molecular weight distribution or abundant gel generation of solutions prepared through a single initiator used for preparing an acrylonitrile solution in the prior art. According to the invention, the initiator comprises 70-100 parts by weight of azodiisobutyronitrile and 1-30 parts by weight of azobisisoheptonitrile. The method well solves the problem through above technical scheme, and can be used for the industrial production of the acrylonitrile solution polymerization

The invention relates to a supported non-metallocene catalyst and a preparation method. The supported non-metallocene catalyst is prepared by the steps of dissolving a non-metallocene ligand in a magnesium compound solution, performing an in-situ reaction with a chemical treatment agent, and dipping a solution of a non-metallocene complex. The preparation method is simple and feasible, the ingredients content of the non-metallocene is adjustable, and the copolymerization effect is substantial. The invention also relates to the application of the supported non-metallocene catalyst in olefin homopolymerisation/copolymerization. Compared with the prior art, the polymerization activity by catalysis of alkene is high, the bulk density of the polymer is high, and the molecular weight distribution is narrow and controllable.

The invention discloses a synthesis method of high-concentration polyepoxysuccinic acid and salt thereof. The method comprises the following main processes: simultaneously adding maleic anhydride and sodium hydrate into water in a mode of feeding in batches; controlling the pH value of solution at 5-7 and the reaction temperature at 40-60 DEG C; adding sodium tngstate into a hydrolysis product as expoxidation catalyst at 50-60 DEG C; carrying out expoxidation reaction by adding hydrogen peroxide; adding sodium hydrate solution at the same time; controlling the pH value at 4-7; finishing the expoxidation reaction; stirring; raising the temperature to above 80 DEG C; adding initiator calcium oxide; and after polymerization, lowering the temperature and filtering to obtain the polyepoxysuccinic acid and salt solution thereof. In the preparation method, a one-pot synthesis is adopted, and therefore, the preparation method has the advantages of simple and unique technology, high product concentration, high raw material conversion rate, ideal molecular weight distribution and favorable industrial operability.

The invention discloses a method for synthesizing a segmented copolymer by coupling enzymatic catalysis and organic catalysis by virtue of a micro reactor, and relates to the field of the synthesis of polymers. The method comprises the following steps: (a) dissolving a monomer 1 and an initiating agent in an organic solvent, pumping an obtained solution into an immobilized enzyme micro reactor, and conducting a full reaction; (b) dissolving a monomer 2 and an organic catalyst in an organic solvent, mixing an obtained solution and reaction liquid outputted from the step (a) in a mixer 4, pumping a mixed solution into a micro-channel reactor 5 and conducting a full reaction; and (c) adding a quenching agent and a third organic solvent to reaction liquid collected from the step (b), and conducting separating and purifying, so as to obtain the pure poly-monomer 1-poly-monomer 2 segmented copolymer. According to the method provided by the invention, the processes of the enzymatic catalysis and the organic catalysis are coupled by virtue of the micro reactor, so that advantages of the enzymatic catalysis and the organic catalysis are integrated, and subsequently reaction efficiency is greatly improved, reaction time is shortened an continuous production is achieved; and the method has the advantages of being safe, efficient, low in energy consumption, high in reaction rate, moderate in reaction conditions and the like.

The invention relates to a supported non-metallocene catalyst and a preparation method. The supported non-metallocene catalyst is prepared by the steps of performing in-situ loading on a non-metallocene complex and dipping a solution. The preparation method is simple and feasible, the ingredients capacity of the non-metallocene is adjustable, and the copolymerization effect is substantial. The invention also relates to the application of the supported non-metallocene catalyst in olefin homopolymerisation/copolymerization. Compared with the prior art, the polymerization activity by catalysis of alkene is high, the bulk density of the polymer is high, and the molecular weight distribution is controllable.

The invention relates to a supported non-metallocene catalyst, a preparation method and an application. The supported non-metallocene catalyst is prepared by the steps of introducing a first non-metallocene complex in a magnesium compound solution, processing by a chemical treatment agent and then reacting with a second non-metallocene complex. The method of the invention has the characteristics of simple and feasible process, controllable content of non-metallocene compounds and substantial copolymerization effect and the like. The invention also relates to the application of the supported non-metallocene catalyst in olefin homopolymerisation/copolymerization. Compared with the prior art, the polymerization activity by catalysis of alkene is high, the bulk density of the polymer is high, and the molecular weight distribution is controllable.

The invention discloses a preparation method of a fluorine-containing high-molecular surfactant, and the preparation method comprises the following steps: enabling an initiator, methacrylic acid-N,N-ethyl dimethylamide, a chain transfer agent and 1,4-dioxane to react at 60-90 DEG C in the presence of the argon to obtain polymethylacrylic acid-N,N-ethyl dimethylamide; adding the initiator, hexafluorobutyl acrylate and 1,4-dioxane, and reacting for 2-8 hours at 65-95 DEG C in the presence of argon; precipitating in n-hexane; drying to obtain the fluorine-containing high-molecular surfactant. By adopting an RAFT polymerization technology, the prepared fluorine-containing high-molecular surfactant contains a fluorine-containing unit similar to the structure of a fluorine-containing monomer, has the characteristics of narrow molecular weight distribution, adjustable structure, low critical micelle concentration, good emulsibility, low foamability and the like, and has broad application prospect in emulsion polymerization.

The invention relates to a polyvinyl chloride production method adding a chain extender to match with a later-stage heating process. The production method is characterized in that during the polymerization reaction process, when the polymerization conversion rate achieves 50%-75%, the chain extender is added into a polymerization kettle by a high-pressure pump, the using quantity of the chain extender is 10-10000ppm of the total quantity of polyvinyl chloride, the material temperature in the polymerization kettle is simultaneously increased by 1-25 DEG C, and the temperature increasing speed is 0.2-3 DEG C/min. Polyvinyl chloride resin produced by adopting the production method disclosed by the invention has a larger molecular weight distribution width index than that of the resin with the same number-average molecular weight and further keeps the excellent processing performance of the resin produced by a pure polymerization later-stage heating process; and simultaneously, the impact strength and tensile strength of a simply supported girder gap of a product are higher than those of the resin produced by adopting the pure polymerization later-stage heating process and equivalent to those of the resin produced by a constant-temperature polymerization process, and good resin processing performance and great product mechanical performance are further realized.