39results about How to "Molecular weight" patented technology

A new polymerization process (atom transfer radical polymerization, or ATRP) based on a redox reaction between a transition metal (e.g., Cu(I) / Cu(II), provides “living” or controlled radical polymerization of styrene, (meth)acrylates, and other radically polymerizable monomers. Using various simple organic halides as model halogen atom transfer precursors (initiators) and transition metal complexes as a model halogen atom transfer promoters (catalysts), a “living” radical polymerization affords (co)polymers having the predetermined number average molecular weight by Δ[M] / [I]0 (up to Mn>105) and a surprisingly narrow molecular weight distribution (Mw / Mn), as low as 1.15. The participation of free radical intermediates in ATRP is supported by end-group analysis and stereochemistry of the polymerization. In addition, polymers with various topologies (e.g., block, random, star, end-functional and in-chain functional copolymers [for example, of styrene and methyl (meth)acrylate]) have been synthesized using the present process. The polymeric products encompassed by the present invention can be widely used as plastics, elastomers, adhesives, emulsifiers, thermoplastic elastomers, etc.

The invention is an adhesive composition comprising: a) an isocyanate functional polyether base prepolymers having a z molecular weight average (Mz) of about 10,000 to about 80,000 g / mole; a carbon black having an average oil absorption number of at least about 80 to at most about 400 cubic centimeters of dibutyl phthalate per 100 grams of the carbon black; (c) reactive silicon in an amount from about 0.001% to about 10% by weight of the adhesive composition; and (d) one or more catalysts for the reaction of isocyanate with hydroxyl groups. The adhesive compositions of the invention surprisingly may have improved sag performance (i.e., decreased sag) when heated, while also making them more easily pumped.

The invention is an adhesive composition comprising: a) an isocyanate functional polyether base prepolymers having a z molecular weight average (Mz) of about 10,000 to about 80,000 g / mole; a carbon black having an average oil absorption number of at least about 80 to at most about 400 cubic centimeters of dibutyl phthalate per 100 grams of the carbon black; (c) reactive silicon in an amount from about 0.001% to about 10% by weight of the adhesive composition; and (d) one or more catalysts for the reaction of isocyanate with hydroxyl groups. The adhesive compositions of the invention surprisingly may have improved sag performance (i.e., decreased sag) when heated, while also making them more easily pumped.

A composition including polyalphaolefins that function as drag reducing agents and a process for the preparation of polyalphaolefins that function as drag reducing agents are disclosed. The process includes contacting alpha olefin monomers with a catalyst system, which includes a catalyst and an activator (co-catalyst) in a reactant mixture. The catalyst is a transition metal catalyst, preferably titanium trichloride, and the co-catalyst may include an alkylaluminoxane, alone or in combination, with a dialkylaluminum halide or a halohydrocarbon. The polymerization of the alpha olefin monomers produces a non-crystalline, ultra-high molecular weight polyalphaolefin having an inherent viscosity of at least 10 dL / g. The addition of the alkylaluminoxane during the polymerization process provides for a non-crystalline, ultra-high molecular weight polyalphaolefin and a more uniform molecular weight distribution of the resulting polyalphaolefin, thereby creating a drag reducing agent superior to known drag reducing agents. A process for forming a drag reducing agent comprising a non-crystalline, ultra-high molecular weight polyalphaolefin having an inherent viscosity of about at least 10 dL / g and a process for reducing drag in a conduit are also disclosed.

Provided are a novel metallocene compound, a catalyst composition including the same, and a method of preparing a polyolefin using the same. The metallocene compound according to the present invention and the catalyst composition including the same may be used for the preparation of a polyolefin, may have excellent polymerization ability, and may produce a polyolefin having an ultra-high molecular weight. In particular, when the metallocene compound according to the present invention is employed, an olefin-based polymer having an ultra-high molecular weight may be polymerized because the metallocene compound shows high polymerization activity even when it is supported on a support.

A manufacturing method of an optical film provided with a convexoconcave structure, comprises the steps of: coating a resin solution including a first resin solved by a solvent onto an endless or roll-like mold provided with a convexoconcave structure, and forming a resin solution layer on the mold; laminating a film substrate onto the resin solution layer to make a laminated film before the solvent in the resin solution layer is completely dried, the film substrate including a second resin, which is capable of absorbing the solvent or is soluble by the solvent; and peeling the laminated film from the mold before the solvent in the laminated film is completely dried.

Improved processes for atom (or group) transfer radical polymerization (ATRP) and novel polymers have been developed and are described. In certain embodiments, novel copolymers comprising a least one polymeric branch or polymeric block with a predominantly alternating monomer sequence are described. Novel copolymers comprising a least one polymeric branch or polymeric block with a gradient monomer structure are described. Additionally, novel copolymers comprising a least one polymeric branch or polymeric block with a predominantly periodic monomer sequence are also described. Novel copolymers having a water soluble backbone and at least two hydrophobic polymeric branches grafted to the water soluble backbone are also described.

Compositions of and methods for separating components of a natural gas stream are disclosed. In one embodiment, the method includes receiving an inlet stream comprising natural gas, the inlet stream having an inlet pressure, and the inlet stream further comprising methane, helium, and an impurity. The method includes allowing the inlet stream to contact a block co-polyimide membrane, the block co-polyimide membrane exhibiting both higher permeability for and higher selectivity for the helium and the impurity than for the methane at the inlet pressure of the inlet stream and separating the methane from the helium and the impurity to create a retentate stream, the retentate stream comprising an increased concentration of methane relative to the inlet stream. The method also includes creating a permeate stream comprising the helium and the impurity at an increased concentration of helium and impurity relative to a concentration of helium and impurity in the inlet stream.

A chemical mechanical polishing aqueous dispersion of the invention includes (A) a first water-soluble polymer having a weight average molecular weight of 500,000 to 2,000,000 and including a heterocyclic ring in its molecule, (B) a second water-soluble polymer or its salt having a weight average molecular weight of 1000 to 10,000 and including one group selected from a carboxyl group and a sulfonic group, (C) an oxidizing agent, and (D) abrasive grains, and has a pH of 7 to 12.

Compositions of and methods for separating components of a natural gas stream are disclosed. In one embodiment, the method includes receiving an inlet stream comprising natural gas, the inlet stream having an inlet pressure, and the inlet stream further comprising methane, helium, and an impurity. The method includes allowing the inlet stream to contact a block co-polyimide membrane, the block co-polyimide membrane exhibiting both higher permeability for and higher selectivity for the helium and the impurity than for the methane at the inlet pressure of the inlet stream and separating the methane from the helium and the impurity to create a retentate stream, the retentate stream comprising an increased concentration of methane relative to the inlet stream. The method also includes creating a permeate stream comprising the helium and the impurity at an increased concentration of helium and impurity relative to a concentration of helium and impurity in the inlet stream.

Production of purified, parenterally administrable starch by washing starch containing more than 85% amylopectin in order to remove surface-localized proteins, lipids and endotoxins, subjecting the starch to a molecular weight reduction by acid hydrolysis, and optionally removing residual water-soluble proteins. Purified starch and microparticles based on such starch.

A chemical mechanical polishing aqueous dispersion of the invention includes (A) a first water-soluble polymer having a weight average molecular weight of 500,000 to 2,000,000 and including a heterocyclic ring in its molecule, (B) a second water-soluble polymer or its salt having a weight average molecular weight of 1000 to 10,000 and including one group selected from a carboxyl group and a sulfonic group, (C) an oxidizing agent, and (D) abrasive grains, and has a pH of 7 to 12.

Production of purified, parenterally administrable starch by washing starch containing more than 85% amylopectin in order to remove surface-localized proteins, lipids and endotoxins, subjecting the starch to a molecular weight reduction by acid hydrolysis, and optionally removing residual water-soluble proteins. Purified starch and microparticles based on such starch.

Provided are a novel metallocene compound, a catalyst composition including the same, and a method of preparing a polyolefin using the same. The metallocene compound according to the present invention and the catalyst composition including the same may be used for the preparation of a polyolefin, may have excellent polymerization ability, and may produce a polyolefin having an ultra-high molecular weight. In particular, when the metallocene compound according to the present invention is employed, an olefin-based polymer having an ultra-high molecular weight may be polymerized because the metallocene compound shows high polymerization activity even when it is supported on a support.

This patent describes a new, simple, and low-cost method to produce aromatic thermosetting copolyester (ATSP) based polymer matrix composites. For this method, the ATSP based composites are directly produced from the blended mixtures of the ATSP oligomer powders with the composite fillers through a high temperature and high pressure curing process. In addition, the fully cured ATSP composite laminates can be bonded together to form thicker multi-material composites. The characterization showed that these ATSP based composites are fully condensed, they have excellent tribological performance (low friction and low wear rate), and they have excellent thermal stability, indicating utility in high performance bearing applications, structural materials, and as an ablative composite material.