508 results about "High molecular weight polymer" patented technology

A process for the crosslinking of at least one polymer selected from polysaccharides and derivatives thereof, which is carried out in an aqueous solvent by the action of an effective and non-excessive amount of at least one crosslinking agent, characterized in that it is carried out on a mixture containing at least one low-molecular weight polymer and at least one high-molecular weight polymer. A process for the preparation of an injectable monophase hydrogel of at least one crosslinked polymer selected from polysaccharides and derivatives thereof is also disclosed. Crosslinked polymers and injectable monophase hydrogels, respectively, are obtainable by each of said processes.

The present invention relates to a method for reducing the polymer and bentonite requirement in papermaking wherein medium and high molecular weight polymers are reacted with bentonite. Further, mechanical shearing of the furnish after polymer addition is not required.

Methods of making ligand-decorated polymer conjugates of therapeutic glycoproteins are described. Improved targeting of glycoproteins to specific tissues is achieved by masking the natural carbohydrate and other surface determinants with high molecular weight polymers, such as, e.g., PEG, polysialic acid, etc., which in turn are decorated with target-specific ligands. In some embodiments, acid-labile linkages in such conjugates or rapidly degradable masking groups allow for the intracellular release of the polymer from the glycoprotein, for example, under conditions found in lysosomes.

The invention provides methods of producing composite polymers by combining fillers with polymers in the presence of preformed high molecular weight polymer. Monomer polymerization can be initiated through the addition of initiators or by reactive chemical groups on the surface of the fibers. The composite materials formed possess superior mechanical properties compared to similar polymer composites made by either purely mechanical mixing or solely polymerization of monomers in the presence of the fillers.

A stent made from an ultra high molecular weight bioabsorbable polymer is disclosed herein. The bioabsorbable polymer can have a Mw greater than 1 million g/mole or greater than 2 million g/mole. Methods of making the ultra high molecular weight polymer stent without degrading the molecular weight are further disclosed.

An antioxidant combined with UHMWPE prior to subjecting the UHMWPE to crosslinking irradiation. In one exemplary embodiment, the antioxidant is tocopherol. After the antioxidant is combined with the UHMWPE, the resulting blend may be formed into slabs, bar stock, and/or incorporated into a substrate, such as a metal, for example. The resulting product may then be subjected to crosslinking irradiation. In one exemplary embodiment, the UHMWPE blend is preheated prior to subjecting the same to crosslinking irradiation. Once irradiated, the UHMWPE blended product may be machined, packaged, and sterilized in accordance with conventional techniques.

A sheath and method of forming is disclosed for a bi-axial oriented made of high molecular weight polymers. The high molecular weight polymers provide a bi-axial oriented sheath with a high hoop stress and a thin wall thickness. A device and method of use is also disclosed for a device for delivery of a self-expanding prosthesis covered by a bi-axial oriented sheath made of high molecular weight polymers. The bi-axial oriented sheath may be moved from a first position constraining the self-expanding prosthesis to a second position releasing the self-expanding prosthesis. During delivery, the device is inserted into the vascular system of the patient, with the self-expanding prosthesis positioned at the location to be treated. The self-expanding prosthesis is then released by moving the bi-axial oriented sheath from the first to second positions, releasing the self-expanding prosthesis.

Methods of controlling the flow index and/or molecular weight split of a polymer composition are disclosed. The method of producing a polymer composition in one embodiment comprises incorporating a high molecular weight polymer into a low molecular weight polymer to form the polymer composition in a single polymerization reactor in the presence of polymerizable monomers, a bimetallic catalyst composition and at least one control agent; wherein the control agent is added in an amount sufficient to control the level of incorporation of the high molecular weight polymer, the level of low molecular weight polymer, or both. Examples of control agents include alcohols, ethers, amines and oxygen.

A supported, heterogeneous catalyst composition for use in polymerization of addition polymerizable monomers to form high molecular weight polymers, comprising: 1) a substrate comprising a solid, particulated, high surface area, surface modified, inorganic oxide compound, 2) a Group 4 metal complex of a bis(hydroxyarylaryloxy) ligand; and optionally 3) an activating cocatalyst for the metal complex.

A method for producing a polypropylene blend from a plastic packaging materials containing high molecular weight polypropylene, other high molecular weight polymers such as polyethylene, low molecular weight polymers and other contaminants. The method includes extraction, solid-liquid separation and liquid-liquid phase separation using various organic solvents. The polypropylene blend has a purity of 95% and has favorable melt flow characteristics, while retaining satisfactory mechanical properties.

The invention relates to a process for the production of paper from a suspension of cellulose containing fibers, and optional fillers, comprising adding to the suspension a low molecular weight cationic organic polymer, a high molecular weight cationic or amphoteric polymer and anionic inorganic particles, forming and draining the suspension on a wire, wherein the low molecular weight polymer has a molecular weight below 700,000 and the high molecular weight polymer has a molecular weight above 1,000,000, said polymers being simultaneously added to the suspension. The invention further relates to a polymer mixture in the form of an aqueous dispersion comprising at least one high molecular weight cationic or amphoteric acrylamide-based polymer having a molecular weight above 1,000,000, at least one low molecular weight cationic organic polymer having a molecular weight below 700,000 and at least one water-soluble inorganic salt, the weight ratio of said high molecular weight polymer to said low molecular weight polymer being within the range of from 9:1 to 1:2.

The invention discloses a high molecular weight guanidine salt and polybasic amine antibiosis type polymer and a preparation method and the application thereof. The polymer comprises a repeated unit structure as right, wherein, X1 and X2 are the same or different polybasic amines; Y is Cl<->, NO3<->, HCO3<-> or H2PO4<->; Z is polyprotic acid, polyprotic acid anhydride or multielement ester. When in preparation, the mixture of polynary amine and guanidine salt is heated for reaction, and then polyprotic acid, polyprotic acid anhydride or multielement ester is added, and the temperature is continuously raised for reaction. The invention solves the problem that the polybasic amine and the guanidine salt react through a main body, thereby being difficulty to obtain a higher molecular weight polymer. In lower reaction temperature and shorter reaction time, by the chain expanding reaction to a polynary amine and guanidine salt prepolymer by the polyfunctionality substance, the high molecular weight guanidine salt and polybasic amine antibiosis polymer is formed. The polymer can be used as the anti fungus agent of the fiber product, the paper product, the non-weaving product and the tissue, etc.

Biodegradable polymeric microparticle compositions containing one or more active agents, especially those useful for treating or preventing or one or more diseases or disorders of the eye, and methods of making and using thereof, are described. The microsphere compositions release an effective amount of the one or more active agents for a period greater than 14 days in vivo, preferably greater than 60 days in vivo, more preferably up to 73 days in vivo, more preferably greater than 90 days in vivo, even more preferably over 100 days in vivo, and most preferably greater than 107 days in vivo. In a preferred embodiment, the microparticle compositions contain one or more active agents useful for managing elevated intraocular pressure (TOP) in the eye. In one embodiment, the microspheres are formed from polylactide-co-glycolide (“PLGA”); in another embodiment, the microspheres are formed from a blend PLGA and poly lactic acid (“PLA”). Relatively hydrophilic, and preferably carboxylated, polymeric materials such as PLGA are used for a drug such as timolol maleate, which is relatively water soluble, to increase drug loading. Higher molecular weight polymers, as well as the ratio of LA (which has a longer degradation time, up to one to two years) to GA (which has a short degradation time, as short as a few days to a week), are used to provide release over a longer period of time. The combination of drug loading and release rate, as well as the minimization of initial burst release, result in prolonged release of a higher amount of drug.

The invention discloses a preparation method of a thermotropic liquid crystal polyarylester fiber, relates to a preparation method of thermotropic liquid crystal polyarylester, and aims to solve the problems that the existing method for preparing the thermotropic liquid crystal polyarylester is complex and the polyarylester fiber is low in tensile strength. The preparation method of the thermotropic liquid crystal polyarylester fiber comprises the following steps: step one, adding p-hydroxybenzonic acid, 2-(4-hydroxyphenyl)-5-carboxylbenzimidazole, acetic anhydride, 4-diethylaminopyridine and an antioxidant into a polymerization kettle for carrying out melt condensation polymerization to prepare a pre-polymer of thermotropic liquid crystal polyarylester; step two, putting the pre-polymer in a rotary kiln under the condition with nitrogen protection for carrying out solid phase polycondensation reaction to obtain high-molecular-weight polymer powder; step three, mixing the high-molecular-weight polymer powder, then cooling and drawing to prepare primary polyarylester fiber; and step four, carrying out heat treatment on the primary polyarylester fiber. The preparation method of the thermotropic liquid crystal polyarylester fiber is simple to operate; the tensile strength of the polyarylester fiber which is finally obtained can reach 4.0-4.5GPa.

A water-soluble, high molecular weight cationic polymer is prepared with polyphyletic composite oxidation-reduction triggering system by: adding multiple aid reagent, triggering methylpropyleneacyloxyethyltrimethyl ammonium chloride, or propyleneamide- propyleneacyloxyethyltrimethyl ammonium chloride, together with propyleneamide water solution to copolymer. The obtained products are water-soluble cationic polymer powder state, viscidity number 13.4-23.4dl/g, METMACS or AETMAC in polymer mol percent content is 0.5% -99.5%, residual monomers content is is less than or equal to 0.1 wt%. This invention has the features of that it adopts domestic industrial grade monomers as raw materials directly, without refine, the obtained products' cationic value is 50-99.5. The products can be used as clay stabilizer, reverse emulsion breaker, slow corrosion agent in petroleum engineering, intensifier, treating agent for wastewater in paper-making industry, water-treating agent and silt dewatering agent in environment protection etc.

A sheet-form, curable pressure-sensitive adhesive is disclosed which includes a high molecular weight polymer (A) such as an acrylic polymer for constituting a pressure-sensitive adhesive component, a compound (B) containing an epoxy group, and a polymerization initiator (C) which is activated upon application of an activation energy such as a light to cause the compound (B) having an epoxy group to undergo a ring-opening polymerization.

The present invention includes a multimodal polyethylene composition has (1) a density of at least about 0.940 g/cm³ as measured by ASTM Method D-1505; (2) a melt flow index (I₅) of from about 0.2 to about 1.5 g/10 min (as measured by ASTM D-1238, measured at 190° C. and 5 kilograms); (3) a melt flow index ratio (I₂₁/I₅) of from about 20 to about 50; (4) a molecular weight distribution, Mw/Mn, of from about 20 to about 40; (5) a bubble stability measured on specified equipment according to specified conditions for a film of about 6×10⁻⁶ m thickness of at least about 1.22 m/s line speed, at least about 45 kg/hr (0.013 kg/sec) output rate, or at least about 0.5 lb/hr/rpm (0.0000011 kg/s/rps) specific output rate or a combination thereof; the composition comprising; and (6) a dart impact on 12.5 micron (1.25×10⁻⁵ m) film of at least 300 g; measured according to ASTM 1709, Method A; (A) a high molecular weight fraction which; (a) is present in an amount of from about 30 to about 70 weight percent (based on the total weight of the composition); (b) has a density of at least about 0.860 g/cm³ as measured by ASTM D-1505; (c) has a melt flow index (I₂₁) of from about 0.01 to about 50 g/10 min (as measured by ASTM D-1238, measured at 190° C. and 21.6 kilograms); and (d) a melt flow index ratio (I₂₁/I₅) of from about 6 to about 12; and (B) a low molecular weight fraction which; (a) is present in an amount of from about 30 to about 70 weight percent (based on the total weight of the composition); (b) has a density of at least about 0.900 g/cm³ as measured by ASTM D-1505; (c) has a melt flow index (I₂) of from about 0.5 to about 3000 g/10 min (as measured by ASTM D-1238, measured at 190° C. and 2.16 kilograms); (d) a melt flow index ratio (I₂₁/I₅) of from about 5 to about 15; and (e) is prepared using a mole ratio of alpha olefin to ethylene of less than or equal to about 0.001:1. The invention also include a process for producing a multimodal ethylene polymer, which process comprises the following steps: (1) contacting in a first gas phase fluidized bed reactor under polymerization conditions and at a temperature of from about 70° C. to about 110° C., a titanium magnesium catalyst precursor, cocatalyst, and a gaseous composition, the gaseous composition having; (i) a mole ratio of alpha-olefin to ethylene of from about 0.01:1 to about 0.8:1; and optionally (ii) a mole ratio of hydrogen to ethylene of from about 0.001:1 to about 0.3:1, to produce a high molecular weight polymer(HMW); and (2) transferring the HMW polymer from step 1 to a second gas phase fluidized bed reactor under polymerization conditions and at a temperature of from about 70° C. to about 110° C., with a gaseous composition having; (i) a mole ratio of alpha-olefin to ethylene of from about 0.0005:1 to about 0.01:1; and (ii) a mole ratio of hydrogen (if present) to ethylene of from about 0.01:1 to about 3:1 to form a polymer blend