10032 results about "Vinyl acetate" patented technology

Methods and compositions for stimulating single and multiple intervals in subterranean wells by diverting well treatment fluids into a particular direction or into multiple intervals using water soluble coated diverting agents are described. The water soluble coating of the diverting material is preferably a collagen, poly(alkylene) oxide, poly(lactic acid), polyvinylacetate, polyvinylalcohol, polyvinylacetate / polyvinylalcohol polymer or a mixture thereof applied as a coating on any number of proppants. The method allows for the diverting of the flow of fluids in a downhole formation during a well treatment, such as during a fracturing process. Following completion of a treatment such as a hydraulic stimulation, the soluble diverting agent can be dissolved and removed by the water component of the well production.

The invention relates to a transdermal analyte monitoring system comprising a medium adapted to interface with a biological membrane and to receive an analyte from the biological membrane and an electrode assembly comprising a plurality of electrodes, wherein the medium is adapted to react continuously with the analyte, an electrical signal is detected by the electrode assembly, and the electrical signal correlates to an analyte value. The analyte value may be the flux of the analyte through the biological membrane or the concentration of the analyte in a body fluid of a subject. The medium may comprise a vinyl acetate based hydrogel, an agarose based hydrogel, or a polyethylene glycol diacrylate (PEG-DA) based hydrogel, for example. The surface region of the electrode may comprise pure platinum. The system may include an interference filter located between the biological membrane and the electrode assembly for reducing interference in the system. The system may comprise a processor programmed to implement an error correction method that corrects for sensor drift.

A coating composition for use in coating implantable medical devices to improve their ability to release bioactive agents in vivo. The coating composition is particularly adapted for use with devices that undergo significant flexion and / or expansion in the course of their delivery and / or use, such as stents and catheters. The composition includes the bioactive agent in combination with a mixture of a first polymer component such as poly(butyl methacrylate) and a second polymer component such as poly(ethylene-co-vinyl acetate).

A catalyst comprising palladium supported on a titania-alumina extrudate is disclosed. The extrudate comprises at least 80 wt % titania and 0.1 to 15 wt % alumina. A palladium catalyst prepared from the titania-alumina extrudate has significantly higher crush strength. Its catalytic performance in vinyl acetate production is improved.

A coating composition for use in coating implantable medical devices to improve their ability to release bioactive agents in vivo. The coating composition is particularly adapted for use with devices that undergo significant flexion and / or expansion in the course of their delivery and / or use, such as stents and catheters. The composition includes the bioactive agent in combination with a mixture of a first polymer component such as poly(butyl methacrylate) and a second polymer component such as poly(ethylene-co-vinyl acetate).

The invention relates to a composite comprising a weight fraction of single-wall carbon nanotubes and at least one polar polymer wherein the composite has an electrical and / or thermal conductivity enhanced over that of the polymer alone. The invention also comprises a method for making this polymer composition. The present application provides composite compositions that, over a wide range of single-wall carbon nanotube loading, have electrical conductivities exceeding those known in the art by more than one order of magnitude. The electrical conductivity enhancement depends on the weight fraction (F) of the single-wall carbon nanotubes in the composite. The electrical conductivity of the composite of this invention is at least 5 Siemens per centimeter (S / cm) at (F) of 0.5 (i.e. where single-wall carbon nanotube loading weight represents half of the total composite weight), at least 1 S / cm at a F of 0.1, at least 1×10−4 S / cm at (F) of 0.004, at least 6×10−9 S / cm at (F) of 0.001 and at least 3×10−16 S / cm (F) plus the intrinsic conductivity of the polymer matrix material at of 0.0001. The thermal conductivity enhancement is in excess of 1 Watt / m-° K. The polar polymer can be polycarbonate, poly(acrylic acid), poly(acrylic acid), poly(methacrylic acid), polyoxide, polysulfide, polysulfone, polyamides, polyester, polyurethane, polyimide, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinyl pyridine), poly(vinyl pyrrolidone), copolymers thereof and combinations thereof. The composite can further comprise a nonpolar polymer, such as, a polyolefin polymer, polyethylene, polypropylene, polybutene, polyisobutene, polyisoprene, polystyrene, copolymers thereof and combinations thereof.

Disclosed is a catalyst. The catalyst comprises palladium, gold, and a support comprising titanium dioxide and tungsten trioxide. The support preferably comprises from 75 wt % to 99 wt % of titanium dioxide and from 1 wt % to 25 wt % of tungsten trioxide. A method for preparing the catalyst is also disclosed. The method comprises impregnating the support with a palladium compound and a gold compound, calcining the impregnated support, and then reducing the calcined support. Further disclosed is a method for preparing vinyl acetate with the catalyst. The catalyst exhibits improved catalytic activity and selectivity.

A cementitious article and a method of making a cementitious article are disclosed. The cementitious article comprises a cementitious component that comprises a polyvinyl acetate type polymer, a monobasic phosphate, and optionally boric acid. Cementitious articles, such as board, are prepared such that the polyvinyl acetate type polymer, the monobasic phosphate, and optionally boric acid can be present in the cementitious core, and / or in dense layers if present. The concentration of the polyvinyl acetate type polymer, monobasic phosphate, and optionally boric acid in the cementitious article can increase from a central region A to peripheral regions B and C, respectively. In some embodiments, the polyvinyl acetate type polymer is a polyvinyl alcohol and the monobasic phosphate is monoammonium phosphate.

A catalyst for synthesizing vinyl acetate from acetylene and acetic acid is prepared from activated carbon, zinc acetate and alkaline bismuth carbonate in mass ratio of 100: (27-40): 0.026 by excessive solution dipping method.

The invention relates to a transdermal analyte monitoring system comprising a medium adapted to interface with a biological membrane and to receive an analyte from the biological membrane and an electrode assembly comprising a plurality of electrodes, wherein the medium is adapted to react continuously with the analyte, an electrical signal is detected by the electrode assembly, and the electrical signal correlates to an analyte value. The analyte value may be the flux of the analyte through the biological membrane or the concentration of the analyte in a body fluid of a subject. The medium may comprise a vinyl acetate based hydrogel, an agarose based hydrogel, or a polyethylene glycol diacrylate (PEG-DA) based hydrogel, for example. The surface region of the electrode may comprise pure platinum. The system may include an interference filter located between the biological membrane and the electrode assembly for reducing interference in the system. The system may comprise a processor programmed to implement an error correction method that corrects for sensor drift.

This invention provides an integrated three step economical process for the production of vinyl acetate monomer (VAM) from acetic acid in the vapor phase. First, acetic acid is selectively hydrogenated over a hydrogenating catalyst composition to form ethyl acetate which is cracked to form ethylene and acetic acid in the second step and in a subsequent step so formed ethylene and acetic acid is reacted with molecular oxygen over a suitable catalyst to form VAM. In an embodiment of this invention reaction of acetic acid and hydrogen over platinum and copper supported on silica selectively produces ethyl acetate in a vapor phase at a temperature of about 250° C., which is cracked over a NAFION catalyst to form ethylene and acetic acid at a temperature of about 185° C., which is mixed with molecular oxygen and reacted over a palladium / gold / potassium catalyst supported on titania to form VAM at a temperature of about 150° C. to 170° C.

The present invention is directed to nanoparticulate compositions comprising a poorly soluble drug and at least one copolymer of vinyl pyrrolidone and vinyl acetate as a surface stabilizer adsorbed to the surface of the drug. Also encompassed by the invention are pharmaceutical compositions comprising a nanoparticulate composition of the invention, methods of making and using such nanoparticulate and pharmaceutical compositions.

The invention discloses a radiation pre-crosslinked ethylene-vinyl acetate (EVA) resin film which comprises the following components in parts by weight: 51-99.58 parts of EVA resin, 0.3-2 parts of organic peroxide crosslinking agent, 0.01-5 parts of assistant crosslinking agent, 0.1-2 parts of antioxidant, 0.01-2 parts of silane coupling agent, 0-40 parts of pigment and 0-40 parts of polyolefin elastomer. The invention also discloses a preparation method of the radiation pre-crosslinked EVA resin film, which comprises the steps of sufficiently mixing 51-99.58 parts of EVA resin, 0.3-2 parts of organic peroxide crosslinking agent, 0.01-5 parts of assistant crosslinking agent, 0.1-2 parts of antioxidant, 0.01-2 parts of silane coupling agent, 0-40 parts of pigment and 0-40 parts of polyolefin elastomer, and adding into an extruder; extruding and forming a film through a T-shaped flat mould; rolling and radiating to obtain the radiation pre-crosslinked EVA resin film. Since the film is partially crosslinked before use, the dimensional stability and heat resistance of the film are remarkably improved, thus the film is suitable for large-scale popularization and application.

Polymeric nanoparticles with a hydrophobic core and a hydrophilic shell are formed from: 1) N-isopropyl acrylamide (NIPAAM), at a molar ratio of about 50% to about 90%, and preferably 60% for specific delivery routes such as oral or parenteral; either water-soluble vinyl derivatives like vinylpyrolidone (VP) or vinyl acetate (VA), or water insoluble vinyl derivatives like methyl methacrylate (MMA) or styrene (ST), at a molar ratio of about 10% to about 30%; and acrylic acid (AA), at a molar ratio of about 10% to about 30%. The formed nanoparticles may be optionally surface functionalized using reactive groups present in AA, including PEGylation, or conjugation of moieties such as chemotherapeutics, contrasting agents, antibodies, radionucleides, ligands, and sugars, for diagnostic, therapeutic, and imaging purposes. The polymeric nanoparticles are preferably dispersed in aqueous solutions. The polymeric nanoparticles incorporate one or more types of medicines or bioactive agents in the hydrophobic core; on occasion, the medicine or bioactive agent may be conjugated to the nanoparticle surface via reactive functional groups. The polymeric nanoparticles are capable of delivering the said medicines or bioactive agents through oral, parenteral, or topical routes. The polymeric nanoparticles allow poorly water soluble medicines or bioactive agents, or those with poor oral bioavailability, to be formulated in an aqueous solution, and enable their convenient delivery into the systemic circulation.

A method of co-producing vinyl acetate and ethyl acetate includes: (a) reacting ethylene, acetic acid and oxygen to form vinyl acetate and at least a minor amount of ethyl acetate; (b) providing a crude product stream containing the vinyl acetate and ethyl acetate of step (a) and acetic acid to a distillation tower; (c) separating the crude product stream into: (i) a vinyl acetate product stream enriched in vinyl acetate with respect to the crude product stream; (ii) an acid recycle stream enriched in acetic acid with respect to the crude product stream; (iii) a mixed sidestream containing vinyl acetate and ethyl acetate, the mixed sidestream being enriched in ethyl acetate with respect to the vinyl acetate product stream; and (d) hydrogenating vinyl acetate in the mixed sidestream to provide an ethyl acetate product stream.

Methods for the catalytic production of vinyl acetate monomer from ethane, ethylene or an ethane / ethylene mixture using a first catalyst containing MoVNbPd, MoVLaPdNbX (where X is Al, Ga, Ge or Si) or MoVNbX (where X is P, B, Hf, Te, As or mixtures thereof) in the first step of oxidation and using a conventional VAM catalyst for the second step. The method produces high yields to acetic acid and vinyl acetate without the coproduction of carbon monoxide. Further-more, the ethylene and acetic acid produced in the first step may be utilized in the second step for VAM production

The invention relates to an active carbon serving as a catalyst carrier and a treatment method and application thereof. After being subjected to heating and dipping treatment in hydrogen peroxide, the specific surface area of the active carbon is 900 to 1,300m<2> / g and the mesopore distribution ratio is 20 to 30 percent. The treatment method has short treatment time and high speed, is convenient to operate and is easy to realize. The micropore size distribution and the micropore surface charge reorganization of the treated active carbon adsorptive catalyst are well improved. The active carbon treated by the method is suitable for serving as the carrier of a synthesis catalyst for the industrial production of vinyl acetate.

Blends of amorphous and semicrystalline polymers having shape memory properties were prepared by blending a crystalline polymer such as poly(vinylidene fluoride), polylactide, poly(hydroxxybutyrate), poly(ethylene glycol) polyethylene, polyethylene-co-vinyl acetate, poly(vinyl chloride), poly(vinylidene chloride) and copolymers of poly(vinylidene chloride) and poly(vinyle chloride) and an amorphous polymer such as poly(vinyl acetate), poly methyl acrylate, poly ethyl acrylate, atactic poly methyl methacrylate, isotactic poly methyl methacrylate, syndiotactic poly methyl methacrylate and other poly alkyl methacrylates. The method for preparing the polymeric materials and applications thereof, for example, as smart medical devices, are also disclosed.

The invention discloses a low-smoke halogen-free flame-retardant polyolefin cable material and a preparation method thereof. The formula of the cable material comprises the following raw materials in percentage by weight: 20-30% of ethylene-vinyl acetate copolymer, 10-20% of linear low-density polyethylene, 3-6% of compatilizer, 50-60% of inorganic flame retardant, 2-5% of synergistic flame retardant, 0.5-1% of coupling agent, 0.2-0.5% of lubricant and 0.2-0.5% of antioxidant. The preparation method of the cable material comprises surface treatment of the inorganic flame retardant, burdening,mixing, milling, extrusion and granulation and other process steps. Compared with the prior art, the cable material disclosed by the invention has the advantages of superior flame retardancy, low smoke, low toxicity, no droplets, good processing performance, good dispersion of the inorganic flame retardant, and better uniformity and surface finish degree.

A coating composition in the form of a one or multi-part system, and method of applying such a composition under conditions of controlled humidity, for use in coating device surfaces to control and / or improve their ability to release bioactive agents in aqueous systems. The coating composition is particularly adapted for use with medical devices that undergo significant flexion and / or expansion in the course of their delivery and / or use, such as stents and catheters. The composition includes the bioactive agent in combination with a first polymer component such as polyalkyl(meth)acrylate, polyaryl(meth)acrylate, polyaralkyl(meth)acrylate, or polyaryloxyalkyl(meth)acrylate and a second polymer component such as poly(ethylene-co-vinyl acetate).

A curable composition includes a functionalized poly(arylene ether), an alkenyl aromatic monomer, an acryloyl monomer, and a polymeric additive effective selected from polystyrene, poly(styrene-maleic anhydride), poly(styrene-methyl methacrylate), polybutene, poly(ethylene-butylene), poly(vinyl ether), poly(vinyl acetate), and combinations thereof. The composition exhibits low shrinkage on curing and improved surface smoothness. It is useful, for example, in the manufacture of automotive body panels.

A process for the manufacturing of a core forming a carrying structure for decorative laminates. The core comprises particles of cured, and optionally foamed, rigid, polyurethane, polyisocyanurate and / or phenolic resin. The particles are bonded to each other in a pressing procedure with a bonding agent comprising an adhesive such as a polymerizing monomer.i) The particles are achieved by grinding cured, and optionally foamed, rigid, polyurethane, polyisocyanurate and / or phenolic resin so that it passes through a 2 mm screen, preferably a 1 mm screen,ii) 100 parts per weight of particles is mixed with 1-100 parts per weight of fiber, the fiber additive having an average length in the range 1-15 mm.iii) The particle-fiber mixture is allowed to absorb a selected amount of water, the amount of water being in the range 1-15% by weight, The water is either added at any stage before the adding of bonding agent, and / or being used as a solvent in the bonding agent, and that,iv) 85 parts per weight of the particle mixture is mixed with 2-15 parts per weight of a bonding agent, the bonding agent selected from the group consisting of,a) A mixture of polyols, such as polyester or polyether, crude methylene diphenyl diisocyanate and possibly a small amount of blowing agent in a ratio forming a polymeric resin with a density in the range 600-1400 kg / m3.b) A formaldehyde based resin such as phenol-formaldehyde resin, urea-formaldehyde resin, melamine-urea-formaldehyde resin, melamine-urea-phenol-formaldehyde resin or phenol-resorcinol-formaldehyde resin, orc) Polyvinyl acetate resin.v)The mixture is applied between the belts of the continuos belt press or the press plates of a static press, optionally with at least one intermediate carrier web, the belts or press plates allowing a mainly uniform and specified material thickness to form. A slightly porous and preconditioned core with a selected water content in the range 0.8-12% is hereby achieved. The invention also relates to a decorative laminate achieved through the process.

A white coated polyester film is provided which has excellent adhesion to the ethylene-vinyl acetate (EVA) typically used as an encapsulation material in solar modules. The good adhesion properties are achieved with a polymeric coating which includes at least one polyurethane and a crosslinker.

The present invention relates to a thermoplastic / natural cellulosic fiber composite, and more specifically to a high molecular weight compatibilizer within that composite resulting in both a high flex strength and high modulus and significant reduction in water absorption. The compatibilizer is preferably a terpolymer comprising: a) 0.5-20 percent by weight of monomer units selected from the group consisting of maleic anhydride, substituted maleic anhydride, mono-ester of maleic anhydride, itaconic anhydride, maleic acid, fumaric acid, crotonic acid, acrylic acid and methacrylic acid; b) 0 to 40 percent by weight of monomer units selected from styrene and functionalized styrene; and c) 40 to 98.5 percent by weight of monomer units selected from the group consisting of C1-8 alkyl acrylates and methacrylates, and vinyl acetate.

The present invention relates to modified rubber powder and its preparation process and use. Structurally, the modified rubber powder has alkyl group, alkenyl group, hydroxyl group, carboxyl group, nitrile group or amino group in the side chain or has side chain connected via double bond reaction to butadiene, polystyrene, vinyl acetate, acrylate, acrylonitrile or other compound. The modified rubber powder has the structural features of rubber retained and thus excellent mechanical performance, physical and chemical performance and machining performance. The introduction of functional group to the side chain results in obviously raised compatibility with other rubber material, plastic and other polymer material, easy grafting reaction and functional group chemical reaction for further modification. In addition, the performances may be regulated via altering the sort and amount of the introduced functional groups.