摘要:
An extrudable polyvinyl alcohol composition useful for packaging and molding applications is prepared by melt blending polyvinyl alcohol and thermoplastic modified starch to provide a product which has reduced water sensitivity, improved modulus and reduced elongation at high relative humidity.A method for extruding the polyvinyl alcohol composition comprises:adding sufficient energy to the polyvinyl alcohol composition to both melt it and essentially eliminate the polyvinyl alcohol crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.The thermoplastic modified starch may be added to the polyvinyl alcohol before or during the melting of the polyvinyl alcohol and elimination of its crystallinity, or the starch may be blended with the thus treated polyvinyl alcohol and then melt extruding the polyvinyl alcohol/starch blend.
摘要:
An extrudable polyvinyl alcohol composition useful for packaging and molding applications is prepared by melt blending polyvinyl alcohol and thermoplastic polyethylene oxide to provide a product which has improved pH stability and salt solution solubility. Useful extruded articles prepared from such compositions include films and containers.A method for extruding the polyvinyl alcohol composition comprises:adding sufficient energy to the polyvinyl alcohol composition to both melt it and essentially eliminate the polyvinyl alcohol crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.The thermoplastic polyethylene oxide may be added to the polyvinyl alcohol before the polyvinyl alcohol is melted and its crystallinity eliminated or blended with the thus thermally treated polyvinyl alcohol and then melt extruding the polyvinyl alcohol/polyethylene oxide blend.
摘要:
An extruable polyvinyl alcohol composition useful for packaging and molding applications is prepared by melt blending polyvinyl alcohol and thermoplastic polyurethane to provide a product which has low water absorptivity, improved impact resistance, and improved low temperature/low humidity tensile properties. Useful extruded articles prepared from such compositions include films and bottles.A method for extruding the polyvinyl alcohol composition comprises:adding sufficient energy to the polyvinyl alcohol composition to both melt it and essentially eliminate the polyvinyl alcohol crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.The thermoplastic polyurethane may be added to the polyvinyl alcohol before the polyvinyl alcohol is melted and its crystallinity eliminated or blended with the thus treated polyvinyl alcohol and then melt extruding the polyvinyl alcohol/polyurethane blend.
摘要:
A vinyl alcohol copolymer comprising the following general structure ##STR1## where R is hydrogen or methyl;R.sup.1 is a C.sub.6 -C.sub.18 hydrocarbyl group not containing an olefinic functionality;x is 70 to 99.5% mole %;y is 0 to 29.5 mole %; andz is 0.5 to 8 mole %.
摘要:
A solid state process for modifying polyvinyl alcohol using a Michael-type addition wherein dry polyvinyl alcohol powder is sprayed with a solution of a monomer capable of Michael-type addition in an amount sufficient to swell the polyvinyl alcohol or maintain its swollen state, but not dissolve or form a slurry of the polyvinyl alcohol. The swollen polyvinyl alcohol is sprayed with a catalyst and the temperature is raised to initiate the reaction between the polyvinyl alcohol and the monomer.
摘要:
An aqueous size composition for cotton-containing textile yarn comprising in an aqueous solution(a) 100 parts polyvinyl alcohol(b) 2-15 parts hydrophobic waxy material(c) 0.2-5 parts ethylene oxide-propylene oxide surfactant which has a surface tension between about 37 and 48 dynes/cm as a 0.1% aqueous solution at 25.degree. C., and a foaming number less than about 20 (ml foam/g solution).degree. F. as a 7% aqueous polyvinyl alcohol solution containing 11.4 parts hydrogenated tallow wax and 2 parts surfactant per 100 parts polyvinyl alcohol.
摘要:
A modified polyvinyl alcohol and a solid state process for producing modified polyvinyl alcohol wherein polyvinyl alcohol powder is sprayed with a sufficient amount of a solution of a polymerizable monomer to swell the polyvinyl alcohol powder but not dissolve it or form a slurry. The swollen polyvinyl alcohol powder is sprayed with a free radical source (an initiator) and the temperature is raised to initiate a reaction between polyvinyl alcohol and the polymerizable monomer.
摘要:
A vinyl acetate copolymer comprising the following general structure ##STR1## where R is hydrogen or methyl;R.sup.1 is a C.sub.6 -C.sub.18 hydrocarbyl group not containing an olefinic functionality;y is 92 to 99.5 mole %; andz is 0.5 to 8 mole %.The vinyl acetate copolymer is hydrolyzed to provide a vinyl alcohol copolymer that can be thermoplastically processed into shaped articles possessing good oxygen gas barrier properties.
摘要:
A vinyl alcohol copolymer comprising the following general structure: ##STR1## wherein R is hydrogen or methyl;X is an organic linking group such as ##STR2## R.sup.1 is C.sub.1 -C.sub.4 alkyl; R.sub.f is a perfluoronated alkyl or poly(alkyleneoxy) group;m is 0 or 1;x is 50-99.9 mole %;y is 0-50 mole %; andz is 0.001-50 mole %.The vinyl alcohol copolymer has excellent solvent barrier properties.
摘要:
A vinyl alcohol copolymer comprising the following general structure: ##STR1## wherein R is hydrogen or methyl;R.sup.1 is hydrogen or methyl;R.sup.2 is hydrogen, C.sub.1 -C.sub.20 alkyl, C.sub.6 -C.sub.20 aryl or C.sub.7 -C.sub.30 alkylaryl;n is a number from 1-1,000;x is 50-99.9 mole %;y is 0-50 mole %; and z is 0.001-50 mole %.