711results about How to "Wide molecular weight distribution" patented technology

A process for making lyocell fibers including the steps of pulping raw material in a digester to provide an alkaline pulp, wherein the raw material includes sawdust in an amount greater than 0% up to 100%; contacting the alkaline pulp including 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 the range of from about 200 to about 1100 without substantially reducing the hemicellulose content or substantially increasing the copper number of the pulp; and forming fibers from the pulp.

A gas-phase olefin polymerization process in a plug flow reactor uses a catalyst system containing a magnesium halide supported titanium-containing component, an organoaluminum component, and at least one external electron donor component; in the process a first external donor component is added to the reactor at an injection point axially near an injection point for the supported transition metal containing component, and at least a second external donor component is added to the reactor axially downstream from the injection point for the first external donor component.

A catalyst used for olefin 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 discloses a high-performance recycled PET/ABS alloy. The alloy comprises the following components in percentage by weight: 30 to 80 percent of recycled PET, 10 to 50 percent of ABS, 1 to 10 percent of reinforcing agent, 2 to 15 percent of compatilizer, 0.5 to 5 percent of flexibilizer, 0.5 to 3 percent of polyhydroxy chemical coupling agent, and 0.1 to 1 percent of antioxidant. The alloy can improve a recycled PET system by using reasonable matching of additives, effects of the polyhydroxy chemical coupling agent, and excellent physical mechanic properties of an ABS system. Therefore, the recycled PET /ABS alloy has the advantages of high compatibility, high tensile strength, high mobility, good machinability and the like, is particularly suitable for producing complicated components and parts and large plates, has a simple process, is suitable for mass production of medium-sized and small enterprises, and has obvious economic benefit and social benefit.

Cyclic organosilicon compounds that may be employed as an electron donor for polymerization catalyst systems, polymerization catalyst systems employing the cyclic organosilicon compounds as an electron donor, methods of making the polymerization catalyst systems, and polymerization processes to produce polyolefin are disclosed. The organosilicon compounds, which are useful as electron donors in polymerization catalyst systems for the production of polyolefins, are represented by the following formula:

wherein Q₁ and Q₂ may be identical or different and are each hetero-atoms selected from the group consisting of N, O, S, Si, B, and P, with the proviso that Q₁ and Q₂ cannot both be N or both be O. R₁ and R₂ may be identical or different and are each hydrocarbon-based substituents to Q₁ and Q₂, respectively. The subscripts m and n are independently 0 to 3. R₃ is an aliphatic, alicyclic or aromatic group. R₄ is a hydrocarbon group with 1 to 6 carbon atoms. R₅ is a bridging group with a backbone chain length between the two hetero-atoms Q₁ and Q₂ being 1-8 atoms. The bridging group is selected from the group consisting of aliphatic, alicyclic, and aromatic bivalent radicals.

A process for forming a coordination catalyst system comprising sequentially or substantially simultaneously contacting: (I) pre-catalyst reactants comprising (a) at least one first ligand-containing reactant; and (b) at least one first transition metal reactant suitable to form at least one metallocene or constrained geometry pre-catalyst compound (e.g., rac-ethylene bis(indenyl)zirconiUm dichloride); an optionally (c) at least one second ligand-containing reactant and (d) at least one second transition metal reactant suitable to form at least one non-metallocene, non-constrained geometry, bidentate or tridentate transition metal compound (e.g., tridentate 2,6-diacetylpyridine-bis(2,4,6-trimethylanaline)FeCl₂) and (II) further contacting, jointly or individually, the pre-catalyst compound(s) and optional bidentate or tridentate compound(s) with at least one support-activator agglomerate (e.g., spray dried silica/clay agglomerate). When individually contacted, the supported catalyst components can be mixed or blended. The resulting transition metal catalyst systems are suitable for addition polymerization of unsaturated monomers, e.g., ethylene and propylene.

The present invention provides one kind of catalyst for polymerization of olefin and the catalyst includes Mg, Ti, halogen and electron donor. The electron donor is at least one kind of dialcohol ester compound.

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.

The invention relates to a filament low-melting-point polyester fiber and a preparation method thereof. The filament low-melting-point polyester fiber is in a skin-core structure, a skin layer is made of low-melting-point polyester; a core layer is made of PET (polyethylene terephthalate); the low-melting-point polyester consists of a terephthalic acid chain segment, an isophthalic acid chain segment, an ethylene glycol chain segment, a diethylene glycol chain segment, a molecular weight modifier chain segment and a 1, 12-Dodecanediol chain segment containing branched chains; a molecular weight modifier corresponding to the molecular weight modifier chain segment is specifically a monoacid series or a diacid series; the preparation method of the filament low-melting-point polyester fiber comprises the following steps: polymerization of the low-melting-point polyester and skin-core composite spinning, so as to obtain the filament low-melting-point polyester fiber. The prepared filament low-melting-point polyester fiber has the advantages that the initial melting point is reduced, the melting speed is increased, the polyester fiber is immediately melted at the corresponding temperature, and the melting effect is good.

The invention relates to a catalyst component for olefin polymerization, a catalyst and application of the catalyst in olefin homopolymerization and polymerization. By using a composite internal electronic donor compound which contains an alpha-cyanosuccinate compound A and a single-functional group or double-functional group compound B which is selected from ester, ether, ketone and ketal exceptfor the compound A as the catalyst of internal electronic donor synthesis, the catalyst has the characteristics of high catalytic activity, high hydrogen adjusting sensitivity, high isotactic index of polymerized products, wide molecular weight distribution and high weight-average molecular weight when being used for propylene polymerization. The favorable performance of the catalyst is beneficial to the preparation of polypropylene and the brand development of products.

The invention relates to polymerization of 1-butene, in particular to a spherical catalyst of polybutylene-1. The catalyst consists of a carrier, an active component and a modifier, wherein the active component is titanium tetrachloride, the carrier is a magnesium chloride spherical carrier and the modifier is an electron donor compound; and the catalyst comprises the major components in percentage by mass of: 1.1-4.5% of Ti and 0.15-12.37% of electron donors. The spherical catalyst suitable for butane-1 polymerization solves the problems that the activity of the general catalyst is low, the normality of polymer is difficult to control, and the molecular weight of the polymer and the molecular weight distribution are difficult to control. The obtained polybutylene polymer has very high steric regularity, the normality of polybutylene is as high as 99%, the crystallinity of the polybutylene-1 polymer is greater than 60% and the fusion point is 130.5 DEG C. The invention can simplify the polymerizing process and save the production cost.

The invention relates to a catalyst component for olefin (co)polymerization, to preparation thereof, to a catalyst comprising the same, and to use thereof in olefin (co)polymerization. The catalyst component of the invention comprises magnesium, titanium, halogen, inner electron donor compound, and alkoxy group derived from a surface modifier, wherein the content of the alkoxy group derived from the surface modifier is in a range of from 0.01 to 3 percent by weight, based on the weight of the catalyst component.

The invention belongs to the field of room temperature self-crosslinking materials, and discloses a room temperature self-crosslinking polyacrylate pressure-sensitive adhesive and a preparation method and application thereof. The method comprises the steps of preparing a pre-emulsion from 85-95 parts of acrylate soft monomer, 5-15 parts of hard monomer, 2-5 parts of functional monomer, 1.3-4 parts of emulgator and 30-55 parts of deionized water by mass fraction; then heating up the pre-emulsion, the deionized water, an initiator, the emulgator and a PH buffer agent for reaction; dripping a chain transfer agent, the pre-emulsion and an initiator solution when the emulsion shows blue light; adding ketone-containing carbonyl monomer, heating up together and reacting; then cooling down and regulating pH value to be 6.5-7.0; and adding hydrazide monomer, stirring and mixing uniformly, so as to obtain the room temperature self-crosslinking polyacrylate pressure-sensitive adhesive. The room temperature self-crosslinking polyacrylate pressure-sensitive adhesive prepared by the method has excellent indexes like excellent initial adhesive force, excellent persistent viscosity force and excellent peel strength, and can be used for preparing labels with good bond performance.

The invention belongs to the technical field of synthesis and preparation of polymer materials, and discloses a synthetic method of triblock polymer, wherein stepwise polymerization (SGB), atom transfer radical polymerization (ATRP) and click chemistry method are combined at first; and 1, 3-dipolar cycloaddition reaction is performed to polymer with azido terminal group and polyurethane prepolymer with alkynyl terminal group to successfully synthesize triblock polymer containing triazole ring. The synthesis method provided by the invention overcomes the defects in traditional block polymer synthesis that reaction conditions are strict, molecular weight distribution is controlled difficultly, and selectable classes of monomers are less, and has the advantages of high conversion rate, mild reaction conditions, narrow molecular weight distribution and strong controllability. The triblock polymer provided by the invention has potential application in ways of medicine slow release, solubilizers and surfactants.

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.

The invention provides components of a catalyst used for CH2=CHR olefin polymerization, wherein R is hydrogen or a C1-C12 alkyl or aryl group. The components of the catalyst include magnesium, titanium, halogen and an electron donor. The electron donor is at least one compound selected from groups represented by a general formula (I); and in the general formula (I), R1 and R2 may be same or different and are respectively selected from the group consisting of a straight-chain or branched-chain C1-C10 alkyl or cycloalkyl group, a C6-C20 aryl or aralkyl group, hydrogen, halogen, an acyl group, an ester group, an amido group and an amino group.

The invention discloses a high isotactic polypropylene alloy material and a preparation method thereof. The material contains 5-98.9 parts by weight of polybutylene, 1-80 parts by weight of polypropylene and 0.1-15 parts by weight of propylene-butene copolymer; the isotacticity of the high isotactic polypropylene is larger than 85%, and the smelting point of the high isotatic polypropylene is 115-129 DEG C; the isotacticity of the high isotactic polypropylene is larger than 85%, and the smelting point of the high isotactic polypropylene is 155-169 DEG C; the propylene-butene copolymer contains a random copolymer and a segmented copolymer of propylene-butene. The preparation method uses a titanium/vanadium supported catalyst and adopts a multistage sequential polymerization manner and specifically comprises the steps of carrying out propylene polymerization or butane-1 polymerization, then initiating butane-1 polymerization or propylene polymerization, and respectively carrying out propylene polymerization or butane-1 polymerization, and so on to synthesize the high isotactic polypropylene alloy material. The material is a powdery or spherical product, and has the advantages of excellent impact resistance, thermal creep resistance and low shrinking percentage of polybutylene, high modulus, high surface hardness and fast setting of polypropylene, and the like.