1569 results about "Polyprenol" patented technology

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.

The present invention relates to a personal care absorbent article comprising at least two substrates each having an internal and external surface, wherein at least one substrate is a fluid permeable bodyside substrate selected from spunbond, meltblown, coform, airlaid, bonded-carded web, spunlace materials and combinations thereof; at least one substrate is an impermeable backsheet; and an absorbent core disposed in between said substrates; wherein at least the external surface of at least one substrate has applied to it a benefit agent selected from an additive composition wherein said additive composition is a polymer dispersion selected from polyolefin dispersions, polyisoprene dispersions, polybutadiene-styrene block copolymer dispersions, latex dispersions, polyvinyl pyrrolidone-styrene copolymer dispersions, polyvinyl alcohol-ethylene copolymer dispersions, and combinations thereof; an enhancement component selected from microparticles, expandable microspheres, fibers, additional polymer dispersions, scents, anti-bacterials, moisturizers, medicaments, soothers and combinations thereof; and combinations thereof.

This invention belongs to rare earth catalyzer for preparing polyisoprene, and its preparation method. This catalyzer is composed by carboxylic acid neodymium, aluminium alkyl, chloride, conjugated diolefine. Mixture ratio of aluminium alkyl, chloride, conjugated diolefine,and carboxylic acid neodymium is 5 - 30:1.0 -4.0:5 - 20:1. This invention could obtain homogeneous phase and stable rare earth catalyzer. This catalyzer possess higher catalytic activity, trigger off isoprene polymerization at higher polymerization temperature, obtain polyisoprene that has high content of syn- 1, 4 structure( not less than 96 percent) and narrow molecular weight distribution ( less than 3.0), and possess tensile crystallinity trait.

A thermoplastic elastomer composition comprised of (a) a thermoplastic resin selected from the group consisting of polyphenylene ether, polypropylene, polyethylene, and polystyrene, (b) a block copolymer selected from the group consisting of styrene-ethylene butylene-styrene, styrene-ethylene propylene-styrene, hydrogenated polybutadiene, hydrogenated polyisoprene, hydrogenated styrene-isoprene random copolymer, styrene-ethylene propylene block copolymer, styrene-ethylene ethylene propylene-styrene and hydrogenated styrene-butadiene random copolymers, (c) a core-shell polymer comprised of a polymeric core and a polymeric shell with the proviso that the polymeric core and/or the polymeric shell may be crosslinked, and (d) an oil.

This invention relates to a pneumatic tire having a built-in sealant layer and its preparation. The sealant layer precursor is a layer of a butyl rubber based composition which contains an organoperoxide. The butyl rubber of said precursor is a copolymer of isobutylene and isoprene containing from about 0.5 to about 5, alternately less than 1, mole percent isoprene. The precursor composition contains carbon black and/or coal dust and may contain a dispersion of liquid conjugated diene polymer (e.g. liquid cis 1,4-polyisoprene polymer), short fibers and/or hollow glass microspheres. A layer of the sealant precursor is built into the tire between a sulfur vulcanized halobutyl rubber innerliner and conjugated diene-based rubber of the tire carcass. The butyl rubber of the sealant precursor is partially depolymerized by the organoperoxide during the elevated temperature vulcanization of the tire to form the built-in sealant layer. In one aspect of the invention, said uncured butyl rubber sealant precursor layer composition has a storage modulus G'(80° C.) in a range of about 100 to about 400 kPa and said partially depolymerized butyl rubber sealant layer composition has a storage modulus G' (80° C.) in range of about 5 to about 50 kPa.

The invention relates to a polydialkene composite rubber of trans-1,4- structure and preparation methods thereof. The composite rubber consists of 10 to 80 mass percent of trans-1,4-polyisoprene and 20 to 90 mass percent of trans-1,4-butadiene-isoprene copolymer, wherein over 90 percent of structural units of all dialkenes in the composite rubber have trans-1,4-structures. The first preparation method comprises the following steps of: homopolymerizing isoprene to obtain trans-1,4-polyisoprene by adopting a Ziegler-Natta catalysis system consisting of MgCl2 supported titanium and organic aluminum compound, and then adding butadiene to synthesize the trans-butadiene-isoprene copolymer. The second preparation method comprises the following steps of: adding mixed monomers of butadiene and isoprene into a polymerization device at the same time, performing copolymerization to obtain the butadiene-isoprene copolymer of the trans-1,4-structure, and continuously polymerizing the isoprene to obtain the trans-1,4-polyisoprene after the butadiene with high polymerization speed is completely consumed. The used polymerization device is a stirring reaction kettle or a screw extruder. The composite rubber has excellent performance such as low rolling resistance, low generated heat, abrasion resistance, particularly fatigue break increment resistance and the like, and is suitable for dynamically used rubber products such as tyres, vibration absorption materials and the like.

A block copolymer, preferably a block copolymer such as poly(isoprene-block-ethylene oxide), PI-b-PEO, is used as a structure directing agent for a polymer derived ceramic (PDC) precursor, preferably a silazane, most preferably a silazane commercially known as Ceraset. The PDC precursor is preferably polymerized after mixing with the block copolymer to form a nanostructured composite material. Through further heating steps, the nanostructured composite material can be transformed into a nanostructured non-oxide ceramic material, preferably a high temperature SiCN or SiC material.

The present invention provides a catalytic system that can be used to prepare by polymerization diene elastomers comprising polyisoprenes and polybutadienes. The invention also provides a process for the preparation of the catalytic system and to a process using the catalytic system to prepare diene elastomers comprising polyisoprenes having a high cis-1,4 linkage content and polybutadienes. The catalytic system according to the invention is based on (a) a conjugated diene monomer, (b) an organic phosphoric acid salt of a rare earth metal, (c) an alkylating agent consisting of an alkylaluminium of the formula AlR₃ or HAlR₂, and (d) a halogen donor consisting of an alkylaluminium halide, and is such that said salt is suspended in at least one inert and saturated aliphatic or alicyclic hydrocarbon solvent and, the “alkylating agent:rare earth salt” molar ratio ranges from 1 to 5.

An elastomer composition includes an elastomer and a carbon black, wherein the carbon black is characterized as having a COAN of between about 90 and 150 ml/100 g, a BET of between 50 and 69 m²/g and a distribution index DI that is greater than 1.15, wherein the DI is a ratio of d_w to d_mode. In particular embodiments, the elastomer may be selected from one or more natural rubbers, one or more synthetic rubbers or combinations thereof For example, the one or more synthetic rubbers may be selected from styrene butadiene rubber, butadiene rubber, polyisoprene rubber, butyl rubber or combinations thereof. Products made from the elastomer composition include tires and other products, particularly tires that include a sidewall, a carcass, a carcass reinforcement, tread and/or an undertread comprising the elastomeric composition.

An aqueous elastomer dispersion includes a dispersed phase and an aqueous phase. The dispersed phase includes an elastomer including curable aliphatic conjugated-diene elastomers, such as polyisoprene, and a minor amount of at least one additive. The aqueous phase includes water and other optional components in either a soluble state or a dispersion state. The aqueous elastomer dispersion may be prepared by dissolving an elastomer, such as rubber, and additives in a solvent mixture and then converting the resulting solution into an aqueous emulsion. The aqueous emulsion is concentrated and the solvent is stripped from it to yield a dilute latex. The dilute latex that is obtained is concentrated again. Articles made from the aqueous elastomer dispersion include medical gloves, condoms, probe covers, dental dams, finger cots, catheters and the like.

A rubber mixture, comprising (A) at least one rubber selected from the group of ethylene-propylene-diene copolymer (EPDM), ethylene-propylene copolymer (EPM), chloroprene rubber (CR), chloropolyethylene (CM), chloro-isobutene-isoprene (chlorobutyl) rubber (CIIR), chlorosulfonyl polyethylene (CSM), etylene-vinyl acetate copolymer (EAM), alkyl acrylate copolymer (ACM), polyester polyurethan (AU), polyether polyurethane (EU), bromo-isobutene-isoprene (bromobutyl)rubber (BIIR), polychlorotrifluoroethylene (CFM), isobutene-isoprene rubber (butyl rubber, IIR), isobutene rubber (IM), polyisoprene (IR), thermoplastic polyester polyurethane (YAU), thermoplastic polyether polyurethane (YEU), silicone rubber with methyl groups on the polymer chain (MQ), hydrogenated acrylonitrile-butadiene rubber (HNBR), acrylonitrile-butadiene rubber (NBR) or carboxylated acrylonitrile-butadiene rubber (XNBR), (B) at least one oxidic filler, and (C) at least one silicon containing azodicarbamide of the general formula I (R 1 ) 3-a (R 2 ) a Si-R I -NH-C(O) -N=N-C (O)-NH-R I -Si(R 1 ) 3-a (R 2 ) a (I) . The rubber mixture is produced by mixing at least one rubber, at least one oxidic filler, and at least one silicon containing azodicarbamide of the general formula I. It may be used for moldings.