Showing papers on "Vinyl acetate published in 1968"

Hydrolyzed ethylene/vinyl acetate copolymer as oxygen barrier layer

Abstract: OXYGEN BARRIER FILMS COMPRISING AN INNER BARRIER LAYER OF A MELT EXTRUDABLE HYDROLYZED ETHYLENE/VINYL ACETATE COPOLYMER AND OUTER LAYERS COMPRISING A BASE OF A THERMOPLASTIC POLYMER AND A HEAT SEALING LAYER OF AN ETHYLENE POLYMER OR COPOLYMER.

Vinyl acetate-crotonic acid-unsaturated ester or ether polymers in hair lacquers and setting lotions

Abstract: COPOLYMERS OF (A) VINYL ACETATE, (B) CROTONIC ACID AND (C) UNSATURATED ESTERS OR ETHERS IN COSMETIC HAIR TREATING COMPOSITIONS.

Process for manufacturing potent pour depressants

Abstract: A method of producing copolymers of ethylene and 28 to 60 weight percent vinyl acetate of 2,000 to 6,000 mol weight for use as pour depressants by charging solvent, vinyl acetate and ethylene to a reactor until the concentration of vinyl acetate in said solvent is 6 to 10 weight percent and the pressure is 700 to 2000 p.s.i., heating to 280* to 340* F. and then adding promoter to start the polymerization and thereafter adding additional promoter and vinyl acetate to maintain the concentration of vinyl acetate in the 6 to 10 weight percent range during the course of the reaction.

Water resistant vinyl acetate copolymer adhesive compositions

Abstract: ADHESIVE COMPOSITIONS CHARACTERIZED BY THEIR OUTSTANDING WATER RESISTANCE, SAID COMPOSITIONS COMPRISING A MIXTURE OF: (A) AN AQUEOUS EMULSION OF A VINYL ACETATE COPOLYMER; (B) POLYVINYL ALCOHOL; (C) AN ACIDIC METAL SALT CURING AGENT

Polyolefin-ethylene/ester copolymer blend compositions

Abstract: A NEW POLYETHYLENE BLEND HAVING IMPROVED STRESS CRACKING PROPERTIES, SAID BLEND COMPRISING A HIGH MOLECULAR WEIGH POLYETHYLENE AND A COPOLYMER OF ETHYLENE AND AN ESTER COMONOMER, SUCH AS ETHYL ACRYLATED, ISOBUTYL ACRYLATE AND VINYL ACETATE, THE COPOLYMER HAVING A MOLECULAR WEIGHT BELOW 15,000 AND THE ESTER COMONOMER MOIETY IN THE RANGE FROM ABOUT 20 TO ABOUT 65 WEIGHT PERCENT. A METHOD FOR PREPARING SAID BLEND WHEREIN THE COPOLYMER IS INTRODUCED INTO THE POLYETHYLENE IN THE MOLTEN STATE AS IT PASSES FROM THE POLYMERIZATION ZONE.

Graft of hydroxyalkyl methacrylate onto polyvinylpyrrolidone

Abstract: A polymeric plastic material suitable for contact lenses, dental liners and other prosthetic devices, intrauterine devices, and other devices to be used in or in the treatment of the body. It is made from a monomer having the formula WHEREINN IS 2 OR 3, POLYMERIZED WITH POLYVINYL PYRROLIDONE OR POLYVINYL PYRROLIDONE/VINYL ACETATE COPOYLMER. The application also discloses procedures for making contact lenses, dental liners, and intrauterine devices from such polymeric material.

Location of some typical vinyl polymers within radiation‐grafted cotton fibers: An electron microscopical survey

Abstract: Electron microscopical observations of radiation-induced rayon–styrene graft copolymers were published by Kaeppner and Huang in 1965. The present paper reports electron microscopical investigations on the relationship of the structure of vinyl–cotton graft polymers to the original morphology of the cotton fiber and into the distribution of the grafted vinyl polymer in the cotton fiber structure. The grafted vinyl monomers investigated in this study were acrylonitrile, styrene, methyl methacrylate, and vinyl acetate. Two radiation-induced procedures were used: simultaneous irradiation grafting and post-irradiation grafting. Ceric ion grafting of acrylonitrile to cotton was included for purposes of comparison. Distribution of the vinyl polymer within the cotton fiber is illustrated by a series of electron micrographs, selected as typical of the particular grafted species under consideration. Results indicate that the diffusion rate of monomer into the cellulose fiber plays an important role in the final distribution of polyacrylonitrile grafts within the fiber. Uniform distribution of polyacrylonitrile in the fiber was achieved by simultaneous irradiation grafting of acrylonitrile on a highly substituted cyanoethylated cotton. In samples of low degree of cyanoethylation the distribution of graft polymer was non-uniform. In grafting initiated by ceric ion the acrylonitrile graft polymer was evenly distributed. Polystyrene–cotton copolymers from grafts, made by simultaneous irradiation of cotton in methanol solutions of the styrene monomer, were uniform throughout the fiber but showed opening of structure associated with the amount of graft formed. Grafting of methyl methacrylate occurred only in the peripheral regions of the fiber; by contrast, grafting of vinyl acetate was uniform throughout the fiber wall. Important factors governing the successful irradiation grafting in cotton fibers are choice of solvent, ratio of monomer to cellulose, nature of prior chemical modification of the cellulose, and total irradiation dosage.

Polyaldehyde crosslinked aliphatic alcohol resins and a process of making temporary wet strength paper and paper made therefrom

Abstract: WET-STRENGTH RESINS ARE PROVIDED WHICH AFFORD TEMPORARY WET STRENGTH TO PAPER PRODUCTS. THE RESINS ARE CATIONIC POLYMERS OF UNSATURATED ALIPHATIC ALCOHOLS REACTED WITH POLYALDEHYDES. THEY ARE PREPARED, FOR EXAMPLE, BY CYANAMIDE MODIFICATION OF POLYVINYL ALCOHOL POLYMERS, FOLLOWED BY GLYOXAL CROSS-LINKING; OR BY COPOLYMERIZATION OF VINYL ACETATE AND DIALLYLDIMETHYLAMMONIUM CHLORIDE, FOLLOWED BY HYDROLYSIS AND GLYOXAL CROSS-LINKING. THESE RESINS ARE ADSORBED ON PAPERMAKING FIBERS IN AQUEOUS SUSPENSION DURING THE PAPERMAKING PROCESS AND IMPART TEMPORARY WET STRENGTH TO RESULTING PAPER PRODUCTS SUCH AS TISSUE, PAPER TOWELS AND THE LIKE.

The emulsion polymerization of vinyl acetate. Factors controlling particle surface area and rate of polymerization

Abstract: An emulsion polymerization system with uniform continuous addition of vinyl acetate monomer, Pluronic F68 surfactant, and persulfate initiator has been examined with variation of the surfactant concentration over a tenfold range. The particle surface area per unit weight of emulsion was found to vary directly as the surfactant/monomer ratio, as also did the emulsion viscosity. At constant polymer/emulsion weight the number of particles per unit emulsion weight varied directly as the cube of the surfactant concentration. It is shown that these relationships apply also to other monomers, such as styrene and methacrylate esters. The solubility of vinyl acetate in a range of Pluronic F68 aqueous solutions was determined, and it was shown that the rate of polymerization is dependent on the solubility of the monomer in the surfactant solution. It is concluded that when a water-soluble initiator is used, polymerization proceeds in the aqueous phase. The principal factors controlling the rate of polymerization in the emulsion polymerization of vinyl acetate are, consequently, the initiating system and the concentration of monomer in the aqueous phase. Solubilization characteristics indicate that the surfactant concentration will have a much greater effect on the less water-soluble monomers, such as styrene, than on the more soluble ones, such as vinyl acetate.

Studies in Polymerization. XVIII. Initiation by Metal Chelates

Abstract: The initiation of vinyl polymerization by manganic acetylacetonate and four related manganic chelates (compounds (II) to (V)) has been studied. In all cases the polymerization involves free-radical intermediates. With Mn(acac) 3 the initiation process is essentially the scission of a ligand as a free-radical, with reduction of the metal to the Mn II state. The change in oxidation number of the metal has been established by magnetic susceptibility measurements. Monomers, as well as solvents capable of coordination, can participate in the rate-determining step. The activation energy and frequency factor for initiation are 26.2 kcal mole -1 and 6.7 x 10 11 s -1 , respectively. Initiation by manganic 1, 1, 1-trifluoroacetylacetonate (V) shows novel features. It is highly selective; the chelate rapidly initiates polymerization of those monomers which polymerize readily anionically, e. g. methyl methacrylate and acrylonitrile, but is very much less effective with other monomers such as styrene and vinyl acetate. A mechanism is proposed in which heterolytic fission of an Mn— O bond is followed by addition of the monomer to the anion; the resulting monomer anion then participates in electron transfer with the manganese III atom forming Mn II and a free-radical which is the initiating species. This mechanism is consistent with the low frequency factor of initiation, 2.9 x 10 6 s -1 for methyl methacrylate. Manganic 1, 1, 1-trifluoroacetylacetonate has been shown to be a strong retarder of the styrene polymerization, the retardation constant at 80°C being 7.3 x 10 4 mole -1 l. s -1 . Retardation is attributable to the additional positive charge on the metal atom in this compound; as expected, it is not significant with methyl methacrylate. Kinetic evidence is presented for ligand transfer reactions in mixtures of Mn(acac) 3 and Mn(facac) 3 .

Metal-Containing Initiator Systems. IX. Radical Polymerizations of Vinyl Monomers by Various Metal Acetylacetonates

Abstract: A study of the polymerization of styrene, methyl methacrylate, acrylonitrile, vinyl acetate, and vinyl chloride initiated by various metal acetylacetonates [Me(acac)x] has been made. It was found that Mn(acac)3 was the most effective initiator, and Co(acac)3, Mn(acac)2, Cu(acac)2, and Cr(acac)3 showed moderate activity for the polymerization of methyl methacrylate at 60°C. However, the other, Me(acac)x, had no effect or served as inhibitors. The addition of some additives such as halogen compounds did not accelerate polymerization of methyl methacrylate by Mn(acac)3, From the results of polymerization and copolymerization of methyl methacrylate by Mn(acac)3, it was concluded that the polymerization proceeded via an ordinary radical mechanism and the activation energy for initiation was 25.2 kcal/mole. The initiation mechanism of vinyl polymerization by Me(acac)x was studied on the basis of the complex formation with the monomer.

Vibration damped sandwich systems

Abstract: A VIBRATION DAMPED SANDWICH SYSTEM COMPRISING TWO HARD PLATES AND INTERPOSED BETWEEN THE PLATES A VIBRATION DAMPING INTERLAYER COMPRISING GRAFT POLYMERS OF STYREN OR OPTIONALLY STYRENE WITH SMALL AMOUNTS OF A COPOLYM ERIZABLE CARBOXYLIC ACID, ESPECIALLY ACRYLIC AND/OR METH ACRYLIC ACID, ON A COPOLYMER OF 30 TO 40% BY WEIGHT OF VINYL ACETATE, 30-40% BY WEIGHT OF N-BUTYL ACRYLATE, 30 TO 10% BY WEIGHT OF DIBUTYL MALEATE AND ABOUT 10% BY WEIGHT OF CROTONIC ACID. D R A W I N G

Alkaline hydrolysis of aqueous polymer dispersions, particularly vinyl acetate copolymers

Abstract: The influence of comonomer species and concentration on the ease of alkaline hydrolysis of vinyl acetate copolymers in the aqueous dispersion form is reported. The comonomers studied include higher vinyl esters, acrylic esters, a fumaric diester, and ethylene. The significance of the emulsion polymerization formulation has also been considered. The rate of hydrolysis is reduced with increasing proportions of comonomers and with increasing length and branching of the alkyl side chain originating from such comonomers. Branched long-chain tertiary vinyl esters reduce not only the rate but also the extent of hydrolysis, being resistant to hydrolysis themselves and also protecting part of the more susceptible vinyl acetate; inhomogeneous copolymers, specially prepared, were less resistant than the more homogeneous copolymer of the same overall composition. The inclusion of quite small amounts, such as 1% by weight, of acid comonomers has a relatively large effect, increasing ease of hydrolysis. For comparison, the behavior of higher vinyl ester homopolymers and methyl methacrylate copolymers with acrylic esters is included. It is concluded that the major factors influencing ease of hydrolysis are steric and other environmental effects arising from the copolymer microstructure.

Hot melt adhesive for polyethylene

Abstract: A HOT MELT ADHESIVE COMPOSITION FOR POLYETHYLENE CONTAINING A HOMOGENEOUS MIXTURE OF DIFFERENT COPOLYMERS OF ETHYLENE AND VINYL ACETATE, ATACTIC LPOLYPROPYLENE, AND PLURAL TACKIFYING RESINS.

Colloidal dispersion of acrylic polymers

Abstract: Aqueous colloidal dispersions of methyl methacrylate polymers are prepared by adding 30-150% of the theoretical amount of ammonium hydroxide required to neutralize the polymer defined below to a mixture comprising water; an interpolymer of methyl methacrylate and either 1-8 by weight of polymer of acrylic and/or methacrylic acid or from 4-7% of maleic and/or itaconic acid and, optionallly, a further comonomer; and (where the second order transition temperature of the polymer is above 25 DEG C.) a comminution agent to render the interpolymer water-dispersible, and agitating the mixture at 40-100 DEG C. until the polymer is colloidally dispersed in the water, at least 95% by number of the polymer particles being within the range 0.01 to 0.1 micron in diameter. Optional monomer components of the interpolymer include alkyl acrylates or haloacrylates of 40016 carbon atoms, alkyl methacrylates of 6-16 carbon atoms, styrene, vinyl acetate and vinyl chloride. The comminution agent, which may also serve as a coalescing agent, is a liquid organic compound capable of swelling or dissolving the polymer, and is preferably watermiscible. Suitable comminution agents include alkanols and hydroxyalkanols, diacetone alcohol, furfuryl and tetrahydrofurfuryl alcohols, halo-alkanols, acetaldehyde, acetone, glycerol, glycidol, glycols, glycol diacetate, glycol ethers and ether-esters, m-dioxane, p-dioxane, and formic, acetic, butyric, pyruvic and dichloroacetic acids. The dispersions may include additional components, e.g. pigments; pigment extenders such as talc, mica, calcium carbonate or clays; pigment dispersing agents such as potassium tripolyphosphate; antifoam agents; mildew inhibitors; and thickening agents such as casein, polyvinyl alcohol, hydroxy ethyl cellulose and carboxy methyl cellulose. The dispersions are suitable for forming coatings or films and for sizing textiles.ALSO:Substrates, e.g. metal or wood, are provided with protective coatings by treating with a composition comprising an aqueous colloidal dispersion of an interpolymer containing units of methyl methacrylate and either 1 to 8% by weight of acrylic and/or methacrylic acid or 4 to 8% by weight of maleic and/or itaconic acid, at least 30 mole % of the acid component being in ammonium salt form and at least 95% by number of the dispersed polymer particles being within the range 0.01 to 0.1 micron in diameter. The interpolymer may also contain other units, e.g. of alkyl acrylates, haloacrylates or methacrylates, styrene, vinyl acetate or vinyl chloride. The required polymer particle size is obtained by a special process for neutralising the parent acid interpolymer (see Division C3), as a result of which the coating composition may contain an organic liquid, preferably water-miscible, e.g. an alkanol, hydroxyalkanol, haloalkanol, diacetone alcohol, furfuryl or tetrahydrofurfuryl alcohol, acetaldehyde acetone, glycerol, glycidol, a glycol or an ether or ether-ester thereof, glycol diacetate, m- or p-dioxane or formic, acetic, butyric, pyruvic or dichloroacetic acid. Optional components may be included, e.g. pigments; pigment extenders such as talc, mica, calcium carbonate or clays; pigment dispersing agents such as potassium tripolyphosphate; anti foam agents; mildew inhibitors; and thickening agents such as casein, polyvinyl alcohol, hydroxy ethyl cellulose and carboxymethyl cellulose.

Preparation and copolymerization of vinyl 10,11-epoxyundecanoate

Abstract: Vinyl 10,11-epoxyundecanoate has been copolymerized with vinyl chloride and vinyl acetate to give film-forming copolymers which are readily converted to insoluble materials.

Sorption and diffusion in asymmetric membranes

Abstract: Polyethylene membranes with nearly linear gradients of grafted poly(vinyl acetate) from one surface to the other have been prepared by radiation-initiated polymerization of sorbed vinyl acetate monomer. Transport of methanol through the modified membrane proceeds at different rates, depending on the direction of flow relative to the gradient of grafted PVAc. A mathematical model has been derived, which gives a quantitative description of the directional transport process. The relationship can be used to predict the transport behavior for single penetrants through asymmetric membranes from knowledge of the properties of the individual components.

Polymeric film coated with vinyl acetate/ethylene copolymer adhesive

Abstract: A POLYMERIC FILM, E.G., POLYVINYL CHLORIDE, IS DISCLOSED WHICH HAS, AS A HEAT SEALABLE COATING ON A SURFACE THEREOF, A VINYLACETATAE/ETHYLENE COPOLYMER CONTAINING EITHER IMINATED CARBOXYLIC ACID GROUPS OR N-METHYLOL AMIDE GROUPS. THE FILM IS PARTICULARLY USEFUL IN A DECORATIVE FILM/ BOARD LAMINATE PREPARED BY A VACUUM FORMING TECHNIQUE.

Stretchable fabric-plastic film laminates

Abstract: LAMINATES, SUITABLE FOR USE IN VACUUM FORMING APPLICATIONS, COMPRISING A STRETCHABLE THERMOPLASTIC FABRIC, E.G., NYLON OR POLYESTER KNIT FABRICS, AND A PLASTIC FILM, E.G., POLYVINLY CHLORIDE, ARE DISCLOSED. THE LAMINATES ARE PREPARED USING VINYL ACETATE/ETHYLENE COPOLYMER ADHESIVE COMPOSITIONS WHICH ARE ORDINARILY APPLIED TO THE PLASTIC FILM IN EMULSION FORM.

Light-sensitive photographic paper

Abstract: PHOTOGRAPHIC PAPER BASE IS SIZED WITH A DISPERSION OF CROSS-LINKED VINYL ACETATE POLYMER TO AVOID MOTTLE, OBTAIN IMPROVED STIFFNESS AND OTHER PROPERTIES. D R A W I N G

Olefin polymer dispersion preparation using oils and waxes as antifoams

Abstract: AN IMPROVED PROCESS FOR THE PREPARATION OF OLEFIN POLYMER DISPERSIONS, SUCH AS ETHYLENE/VINYL ACETATE COPOLYMER DISPERSIONS, IS PROVIDED. THE IMPROVEMENT COMPRISES ADDING VEGETABLE OILS OR REFINED SOLID OR LIQUID HYDROCARBONS DERIVED FRO PETROLEUM SUCH AS PARAFFIN WAXES OR LIGHT AND HEAVY MINERAL OILS TO SUPPRESS FOAM AT A SPECIFIC TIME DURING SOLVENT EVAPORATION.

Reactivities of monomers towards the phenyl radical

Abstract: Labelled benzoyl peroxide has been used to initiate at 60°C polymerizations of styrene, methyl methacrylate and vinyl acetate in the presence of dimethylformamide; the relative numbers of benzoyloxy and phenyl end-groups have been determined in the polymers. The effects of dimethylformamide upon the balance between the two types of end-group can be explained if there is a significant primary radical transfer between that substance and the phenyl radical. It is possible to compare the reactivities of monomers towards the phenyl radical using the primary radical transfer process as the reference reaction. At 60°C the relative values of the velocity constants for the addition of the phenyl radical to styrene, methyl methacrylate and vinyl acetate are 1.0, 1.7 and 0.08 respectively. It is confirmed that the reactions of the phenyl radical are little affected by polar factors.

Film forming copolymers of ethylene vinyl chloride and a vinyl ester and their production

Abstract: AQUEOUS DISPERSIONS OF COPOLYMERS WHCIH ARE CAPABLE OF DRYING TO FORM FILMS HAVING GOOD RESISTANCE TO HYDROLYSIS BY AQUEOUS ALKALI, THE COPOLYMERS ARE FORMED FROM ETHYLENE, VINYL CHLORIDE AND VINYL ESTER OF AN ORGANIC ACID. E.G. VINYL ACETATE, AND CONTAINS 5-25% ETHYLENE UNITS 10-35% VINYL CHLORIDE UNITS AND 40-85% VINYL ESTER UNITS.

Mode of termination in the copolymerization of vinyl acetate–isobutyl methacrylate and methyl methacrylate–methyl acrylate at 60°C

Abstract: The mode of termination in the vinyl acetate–isobutyl methacrylate (VA–IBMA) and methyl methacrylate–methyl acrylate (MMA–MA) copolymerization systems has been investigated at 60°C. by using the dye-interaction technique for functional endgroup estimation. The results show that pairs of poly(vinyl acetate) radicals interact almost exclusively through a disproportionation mechanism. In the homopolymerization of methyl methacrylate and methyl acrylate, about 1.16 and 1.22 carboxyl-containing endgroups per polymer molecule have been estimated, which shows the predominance of disproportionation over combination in these termination reactions. In poly(isobutyl methacrylate) about 1.55 tagged initiator fragments per chain indicate that 29% of the total radicals terminate through the disproportionation mechanism. Cross termination in the (VA-IBMA) copolymerization system occurs almost entirely through combination for monomer feeds richer in isobutyl methacrylate content while for the MMA-MA system, combination is more important at intermediate monomer feed ratios. These results have been discussed in the light of different explanations for the reaction mechanism.

Ethylene-vinyl acetate copolymer latex prepared with acrylic seed

Abstract: VINYL ACETATE AND ETHYLENE ARE POLYMERSIED IN AN EMULSION OF A SMALL AMOUNT OF A SEED POLYMER OBATINED BY COPOLYMERISING AN ESTER OR NITRILE OF METHACRYLIC OR ACRYLIC ACID, OPTONALLY WITH A POLYMERISABLE CARBOXYLIC ACID.