716results about How to "Wide molecular weight distribution" patented technology

The present invention provides one kind catalyst component for CH2=CHR olifine polymerization, where R is H or alkyl radical or aryl radical of C1-C6. The catalyst component contains Mg, Ti, halogen and electron donor.

The present invention provides a process for preparing high melt strength propylene polymer by direct polymerization, comprising that a propylene polymer with wide molecular weight distribution and containing “very high molecular weight fraction” can be prepared by controlling the species and ratios of the external electron donors in the Ziegler-Natta catalyst system at different reaction stages according to the requirment for different molecular weight fractions in the different propylene polymerization stage of the series operation, and said polymer has excellent mechnical properties, especially with very high melt strength. The present invention also provides a propylene homopolymer with high melt strength, comprising the following features: (1) the MFR is 0.2-10 g / 10 min at 230° C. with a load of 2.16 kg; (2) the molecular weight distribution Mw / Mn is 6-20; (3) the content of the fraction with a molecular weight higher than 5,000,000 is higher than or equal to 0.8 wt %; (4) Mz+1 / Mn is higher than or equal to 70. Said homopolymer can be used in the preparation of foam products, thermoforming products, biaxial stretching films, blown films and blow-molded products.

This invention relates to a catalyst system which is used for alkenes polymerizing or copolymerization, it includes solid catalyst composition A that contains titanium and organic Aluminum compound B, silicoorganic compound C, in the composing process of catalyst composition A, use aldyl ester of aryl group mon-carboxylic acid and aldyl ester of fatty series or multielement carboxylic acid of aryl group for reasonable combination, among them aldyl ester of aryl group mon-carboxylic can play a role of assisting separating agent, it is useful to separate catalyst particle; Meanwhile it is used as electron donor, it also can load on the surface of catalytic agent together with compound of multielement carboxylic esters, improve the surface structure of catalytic agent, thus improve the catalyzing function of catalytic agent. This catalytic agent that is used for propylene polymerizing has high catalytic activity and anti- impurity function, particle appearance of catalytic agent is good, particles distribute narrowly, hydro-adjusting function of catalytic agent is good, it is useful for many polymerizing technology such as seriflux method, noumenon method and gas method, molecular weight distribution of polymer is narrow, particle appearance of polymer is good, fine grits is little; Its fine anti-impurity function can effectively reduce production cost.

The invention provides a catalyst component for olefin polymerization. The method for preparing the catalyst component comprises the following steps of: (1) dissolving magnesium halides into a solvent system consisting of an organic epoxy compound, an organic phosphorous compound and an inert diluent to obtain a uniform solution, mixing the uniform solution and a titanium compound, precipitating solids in the presence of an auxiliary precipitation agent, and adding an organic alcoholic compound before the solids are precipitated; and (2) treating the precipitated solids by using at least one electron donor compound diatomic alcohol ester compound to make the compound attached to the solids; and treating the solids by using the titanium compound and the inert diluent. The catalyst of the invention has a simple preparation method; when the catalyst is used for the olefin polymerization, particularly propylene polymerization, the polymerization activity of the catalyst is obviously improved; and the molecular weight distribution of the polymers obtained from the catalyst is quite wide.

The invention relates to a method for preparing branched high ethenyl butadiene rubber with molybdenum catalyst, recombining macromolecular monomer prepared through polymerization of molybdenum catalyst butadiene atom free radical or butadiene anion initiated by organic lithium, naphthalene sodium, with coordinate polymerization of butadiene or original position polymerization, to prepare said product with controllable construction. The method is characterized by simple process, special construction of polymer, proper molecular weight and molecular distribution, more than 80% of ethenyl content, controllable property, length, distribution and degree of branching of branch chain in a certain range, good processing behavior and physical mechanics property and low production cost.

A process for making a composition for conversion to lyocell fiber where the process comprises pulping a raw material in a digester to provide an alkaline pulp, wherein the raw material comprises sawdust in an amount greater than 0 % up to 100 %; and contacting the alkaline pulp comprising cellulose and at least about 7 % hemicellulose under alkaline conditions with an amount of an oxidant sufficient to reduce the average degree of polymerization of the cellulose to within the range of from about 200 to about 1100, without substantially reducing the hemicellulose content of the pulp or substantially increasing the copper number.

A catalyst used for olifin polymerizing reaction CH2=CHR, where R is hydrogen or C1-C6 alkyl or aryl, contains Mg, Ti, halogen and electron doner which may be at least one dialkoxide compound.

The invention relates to an inorganic-modified chitosan composite type polymeric flocculant. The inorganic-modified chitosan composite type polymeric flocculant is characterized in that a method for preparing the composite type polymeric flocculant comprises the following steps of: taking polyacrylamide-modified chitosan as a raw material and methacryloyloxyethyl trimethyl ammonium chloride, maleic acid and ceric ammonium nitrate as initiators, synthesizing a modified chitosan copolymer under a faintly acidic condition and blending the modified chitosan copolymer with polymerized ferric chloride and polymerized aluminium chloride to obtain the inorganic-modified chitosan composite type polymeric flocculant. According to the steps, the mass ratio of modified starch to the chitosan is (1-2): 1, the reaction temperature is 50-60 DEG C, the reaction time is 2-3 hours, and the use amount of the initiators accounts for 0.02 part of the total mass of the system. The inorganic-modified chitosan composite type polymeric flocculant prepared by using the method has the characteristics of high efficiency, low cost and low secondary pollution to environment; and aiming at different sludges, compared with a conventional flocculant, the inorganic-modified chitosan composite type polymeric flocculant disclosed by the invention has the advantages that the wastewater decoloring rate and the wastewater deturbidity rate can reach more than 99 percent under the condition of low use amount.

The invention relates to emulsifier systems for cosmetic and pharmaceutical oil-in-water emulsions comprising high molecular weight organomodified polysiloxanes with a dispersion index greater than 1.6.

A catalyst for olefin polymerization of the present invention includes a solid titanium catalyst component (I) including titanium, magnesium, halogen, and a cyclic ester compound (a) represented by the following formula (1):wherein n is an integer of 5 to 10; R2 and R3 are each independently COOR1 or R, and at least one of R2 and R3 is COOR1; a single bond (excluding Ca—Ca bonds, and a Ca—Cb bond in the case where R3 is R) in the cyclic backbone may be replaced with a double bond; a plurality of R1's are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms; and a plurality of R's are each independently a hydrogen atom or a substituent, but at least one of R's is a hydrogen atom, and an organometal compound catalyst component (II). When this catalyst for olefin polymerization is used, an olefin polymer having a broad molecular weight distribution can be produced.

The invention relates to a preparation method of a mud-resistant type polycarboxylate superplasticizer. First, polyethylene glycol monomethyl ether and acrylic acid are used as raw materials and synthetized into polyethylene glycol monomethyl ether methyl acrylate. Then, the prepared polyethylene glycol monomethyl ether methyl acrylate is copolymerized with mixed liquid which is made from the acrylic acid and diacrylamide sodium dimethallyl sulphonate and mixed liquid which is made from ammonium persulfate and mercaptoethanol, alkaline compounds are added to regulate a pH value to 7-8 after reaction, and the mud-resistant type polycarboxylate superplasticizer is obtained. In the preparation method, technical parameters and conditions, such as raw material ratio, the used amount of chain transfer agents and initiators, copolymerization temperature, time and the like are determined. The reaction conditions are mild, the adopted equipment is simple, the equipment investment is small, the technology is reasonable, and the operation is simple and favorable for industrial production.

The invention provides a concrete polycarboxylate water reducing agent and a preparing method thereof. The concrete polycarboxylate water reducing agent is a polymer copolymerized by a monomer A and a monomer B, wherein the weight-average molecular weight of the polymer ranges from 5,000 to 30,000. The chemical structural formula is shown in the specification, wherein m is an integer ranging from 14 to 66, n is an integer ranging from 0 to 40, R1 is H or COOH, and R2 is H or CH3. The performance is stable, the water-reducing rate is high, and cement adaptation is high; the concrete polycarboxylate water reducing agent has the excellent water reducing performance and the excellent slump retaining performance, and has the advantages that the preparing process is simple in technology, time is short, reaction energy consumption is low, operability is high, and pollution to the environment is avoided.

A Ziegler-Natta catalyst composition comprising a solid mixture formed by halogenation of: Al) a spray-dried catalyst precursor comprising the reaction product of a magnesium compound, a non-metallocene titanium compound, and at least one non-metallocene compound of a transition metal other than titanium, with A2) an organoaluminium halide halogenating agent, a method of preparing, precursors for use therein, and olefin polymerization processes using the same.