Showing papers on "Vinyl acetate published in 1986"

Copolymerization of ω-Unsaturated Oligo(Methyl Methacrylate): New Macromonomers

Abstract: The free-radical copolymerization of ω-unsaturated oligo(methyl methacrylate) (1) with each of ethyl acrylate, styrene, methyl methacrylate, acrylonitrile, and vinyl acetate have been investigated. Incorporation of (1) into the polymer was observed in all cases although the molecular weights of the copolymers were substantially lower than those of the homopolymers obtained in the absence of (1) but under otherwise identical conditions. These experiments, together with a product study of the reactions of (1) with cyanoisopropyl radicals, have shown that the addition of free radicals to the double bond of (1) occurs readily. The sterically hindered radical so formed, however, undergoes facile β-scission, resulting in the termination of chains (chain transfer) in competition with chain propagation. The implications of these findings to the usefulness of (1) in the synthesis of graft copolymers and their relevance to the chemistry of free-radical polymerizations when methyl methacrylate is employed a...

Preparation of water-soluble copolymers containing vinylamine units, and their use as wet strength agents and dry strength agents for paper

Abstract: Water-soluble copolymers containing copolymerized vinylamine units are prepared by copolymerizing (a) from 95 to 10 mol % of N-vinylformamide and (b) from 5 to 90 mol % of an ethylenically unsaturated monomer from the group consisting of vinyl acetate, vinyl propionate, C 1 -C 4 -alkyl vinyl ethers, the esters, nitriles and amides of acrylic acid and methacrylic acid and N-vinylpyrrolidone, and then eliminating from 30 to 100 mol % of the formyl groups from the copolymer. Preferred copolymers are copolymers of N-vinylformamide and vinyl acetate, in which from 30 to 100 mol % of the monomer units are hydrolyzed. The copolymers are used in papermaking to increase the dry strength and wet strength of the paper.

Use of graft copolymers of polyalkylenoxides and vinyl acetate as anti-redeposition agents in the washing and post-treatment of textiles containing synthetic fibres

Abstract: Verwendung von Pfropfcopolymerisaten, die erhaltlich sind durch Pfropfen von Polyalkylenoxiden eines Molekulargewichts (Zahlenmittel) von 2000 bis 100.000 mit Vinylacetat im Gewichtsverhaltnnis 1:0,2 bis 1:10 und deren Acetatgruppen gegebenenfalls bis zu 15 % verseift sind, als Vergrauungsinhibitoren beim Waschen und Nachbehandeln von Synthesefasern enthaltendem Textilgut. Use of graft copolymers obtainable by grafting polyalkylene oxides having a molecular weight (number average) of 2,000 to 100,000 with vinyl acetate in Gewichtsverhaltnnis 1: 0.2 to 1:10 and the acetate groups optionally up to 15% are hydrolyzed, as graying inhibitors in the washing and aftertreatment containing textile material of synthetic fibers.

Ophthalmic solution for treatment of dry-eye syndrome

Abstract: A synergistic combination in an aqueous solution of a partially hydrolyzed poly(vinyl acetate) and a fully hydrolyzed poly(vinyl acetate), i.e. poly(vinyl alcohol), exhibiting a low surface tension at the water-air interface, while forming a completely wettable absorbed layer over hydrophobic solids. The combination is used as part of an ophthalmic solution including a hydrophilic low viscosity polymer, poly(N-glucose) or poly(N-vinyl pyrrolidone) with higher than normal oncotic pressure in a physiologically compatible electrolytic solution base. The formulation is effective in treating the two major underlying causes of the dry eye syndrome; ocular surface disorder and tear film abnormalities resulting in tear film instability. It can also be effective as an aqueous vehicle for topically used ophthalmic drugs or nutrients.

Miniemulsion copolymerization of vinyl acetate and butyl acrylate. I: Differences between the miniemulsion copolymerization and the emulsion copolymerization processes

Abstract: Differences between the emulsion copolymerization and miniemulsion copolymerization processes, in terms of emulsifier adsorption, emulsion stability, polymerization kinetics, copolymer composition and dynamic mechanical properties were studied for the comonomer mixture of 50:50 molar ratio vinyl acetate (VA+)—butyl acrylate (BuA), using sodium hexadecyl sulfate (SHS) as a surfactant and hexadecane (HD) as a co-surfactant. The use of hexadecane with the appropriate SHS initial concentration led to a higher adsorption of surfactant, smaller droplet size, higher stability of the emulsions, lower polymerization rates, and larger latex particle size. The copolymer composition during the initial 70% conversion was found to be less rich in Vac monomer units for the miniemulsion process. The dynamic mechanical properties of the copolymer films showed less mixing between the BuA-rich core and the VAc-rich shell in the miniemulsion latexes compared to the conventional latex films.

Method of stabilizing aqueous systems

Abstract: A process for stabilizing aqueous systems containing scale forming salts and inorganic particulates by adding to such systems an effective amount of selected low molecular weight water soluble polymers containing from about 10 to about 84 weight percent (meth)acrylic acid units, greater than 11 to less than about 40 weight percent acrylamido alkyl or aryl sulfonate units and from at least about 5 to about 50 weight percent of one or more units selected from vinyl esters, vinyl acetate and substituted acrylamides, is provided. The terpolymers and interpolymers used in the process provide improved phosphate, iron and zinc stabilization while maintaining their water solubility. Certain preferred polymers also exhibit a high degree of hydrolytic stability at high pH conditions.

Polymeric coating for container induction innerseal

Abstract: Tamper-resistant inner seals that bond firmly to the lips of lidded and capped glass and plastic containers The innerseals incorporate a metallic foil having a heat-sealable adhesive applied to one surface thereof The heat-sealable adhesive comprises a paraffin wax or blend of paraffin wax and microcrystalline wax, polystyrene or derivative thereof, rosin or derivative thereof, and at least one high molecular weight polymeric material selected from the group consisting of ethylene/acrylic acid copolymers, ethylene/vinyl acetate copolymers, ethylene/methacrylate copolymers, and ethylene/vinyl acetate/methacrylic acid terpolymers, and blends thereof

Electrical conductivity of carbon black filled ethylene-vinyl acetate copolymer as a function of vinyl acetate content

Abstract: The electrical conductivity of carbon black filled ethylene-vinyl acetate copolymer was measured as a function of carbon and vinyl acetate (VAc) content. For the composites whose matrices contain less than 32 wt% ofVAc content, a sharp break point of the relation between carbon content and conductivity was observed. The conductivity jumps as much as ten orders of magnitude at the break point. The critical carbon content corresponding to the break point can essentially be predicted by our previous model. This model was derived under certain assumptions, the most important of which is that when the interfacial excess energy introduced by carbon particles into the polymer matrix reaches a “universal value”,Δg*, the carbon particles begin to coagulate so as to avoid any further increase of energy and to form networks which facilitate electrical conduction. On the other hand, for the composites whose matrices contain more than 32 wt% ofVAc content, a sharp break of the relation between the carbon content and conductivity cannot be observed and conductivity increases continuously with increasingVAc content. In this region ofVAc content, carbon particles were dispersed well in theVAc rich matrices. This is because the presence of polar groups in aVAc component enhances its bonding to conductive fillers. In this case, the interfacial excess energy,Δg, seems to be the caseΔg≤0. Better dispersibility of fillers in this region ofVAc content can be shown from an electron micrograph (TEM).

Large Dielectric Relaxations in an Alternate Copolymer of Vinylidene Cyanide and Vinyl Acetate

Abstract: An alternate copolymer of vinylidene cyanide and vinyl acetate has been investigated dielectrically at temperatures above Tg ~170°C A remarkable relaxation was observed in the 1 Hz to 10 kHz frequency range due to a separation from coexisting contributions as a result of the dc conductivity The relaxation time depends upon the temperature in the WLF according to the characteristics of the micro-Brownian motions of molecular segments The relaxation strength was found to reach 125, resulting in an unusually high dielectric constant Such a large relaxation strength is an indication of some cooperative effects in relation to dipolar motions Cooling to below Tg in the presence of a high electric field creates a large remanent polarization which is consistent with the strong piezoelectric activity reported for this copolymer

Detergents containing graft copolymers of polyalkylene oxides and vinyl acetate as antiredeposition inhibitors

Abstract: Detergents contain added graft copolymers which have an antiredeposition action and are obtainable by grafting polyalkylene oxides having a number average molecular weight of from 2000 to 100,000 with vinyl acetate in a weight ratio of from 1:0.2 to 1:10, and up to 15% of whose acetate groups may be hydrolyzed.

Aqueous ink recording sheet

Abstract: An aqueous ink recording sheet is described which is prepared by coating on the surface of a substrate sheet a resin composition containing as the chief ingredient a mixture comprising (A) 10 to 90 wt % of photo polymerizable, double bonded anionic synthetic resin, and (B) 90 to 0 wt % of partially or completely saponified polyvinyl alcohol, or partially or completely saponified polymer resin composed of 20 to 100 wt % of vinyl acetate and 80 to 0 wt % of other polymerizable monomer or derivatives thereof, and/or (C) 90 to 0 wt % of homopolymer resin of N-vinylpyrrolidone or copolymer resin of other polymerizable monomer therewith, with the weight ratio of (A)/[(B)+(C)] being 90/10 to 10/90, drying the coated resin composition, and then curing the resin composition by the irradiation with actinic rays so as to form a resin coating layer on the substrate. The aqueous ink recording sheet of the present invention is not only capable of recording distinctly and sharply the multicolor full color copy that is an advantageous point in ink jet process but also excellent in both the adsorbency and the dryness against the ink.

Process for preparing vinyl amine-containing water soluble copolymers and their use as wet and dry strength agents for paper

Abstract: Verfahren zur Herstellung Vinylamin-Einheiten einpolymerisiert enthaltenden wasserloslichen Copolymerisaten durch Copolymerisieren von a) 95 bis 10 Mol-% N-Vinylformamid und (b) 5 bis 90 Mol-% eines ethylenisch ungesattigten Monomeren aus der Gruppe Vinylacetat, Vinylpropionat, C₁- bis C₄-Alkylvinylether, der Ester, Nitrile und Amide von Acrylsaure und Methacrylsaure und N-Vinylpyrrolidon und anschliesendes Abspalten von 30 bis 100 Mol-% der Formylgruppen aus dem Copolymerisat. A process for the preparation of polymers containing vinylamine units water-soluble copolymers obtained by copolymerizing a) from 95 to 10 mol% of N-vinylformamide and (b) 5 to 90 mol% of an ethylenically unsaturated monomer from the group vinyl acetate, vinyl propionate, C₁- to C₄- alkyl vinyl ethers, the esters, nitriles and amides of acrylic acid and methacrylic acid and N-vinylpyrrolidone and subsequent cleavage from 30 to 100 mol% of the formyl groups from the copolymer. Vorzugsweise kommen Copolmerisate aus N-Vinylformamid und Vinylacetat in Betracht, deren Monomereneinheiten zu jeweils 30 bis 100 Mol-% hydrolysiert sind. Preferably Copolmerisate of N-vinylformamide and vinyl acetate are considered whose monomer units are hydrolyzed to each 30 to 100 mol%. Die Copolymerisate werden bei der Herstellung von Papier zur Erhohung der Trocken- und Nasfestigkeit des Papiers verwendet. The copolymers are used in the manufacture of paper to enhance the dry and wet strength of the paper.

A dielectric study of poly(ethylene‐co‐vinylacetate)–poly(vinyl chloride) blends. I. Miscibility and phase behavior

Abstract: Measurements of the complex permittivity were used to study miscibility and phase behavior in blends of poly(vinyl chloride) (PVC) with two random ethylene—vinyl acetate (EVA) copolymers containing 45 and 70 wt % of vinyl acetate. The dielectric β relaxation of the pure polymers and blends was followed as a function of temperature and frequency for different blend compositions and thermal treatments. Blends of EVA 70/PVC were found to be miscible for compositions of about 25% EVA 70 and higher. Blends of lower EVA 70 content showed evidence of two-phase behavior. EVA 45/PVC blends were found to be miscible only at the composition extremes; at intermediate compositions these blends were two-phase, partially miscible. Both blend systems showed lower critical solution temperature behavior. Phase separation studies revealed that in the EVA 45/PVC blends, PVC was capable of diffusing into the higher Tg phase at temperatures below the Tg of the upper phase. In the blends, ion transport losses were significant above the loss peak temperatures, and in the two-phase systems, often obscured the upper temperature loss process. It was shown possible, however, to correct the loss curves for this transport contribution.

Polyester resin composition for forming an impact resistant article

Abstract: A polyester resin composition for forming an impact resistant article is described, comprising from 40 to 97 parts by weight of polyethylene terephthalate and from 3 to 60 parts by weight of at least one polyester selected from (1) an ethylene terephthalate-based polyester comprising from 5 to 25 wt % of at least one dibasic acid represented by formula (I) ##STR1## wherein A and B each represents a hydrogen atom, an alkyl group, or a phenyl group, and n is an integer of not less than 10, and ester bond-forming derivatives, (2) an ethylene terephthalate-based polyester comprising 3 to 25 wt % of at least one polyalkylene glycol having a molecular weight of from about 500 to 20,000, and (3) polyarylate, which composition further contains, per 100 parts by weight of the polyester, (a) from 0.05 to 10 parts by weight of at least one of an inorganic crystal nucleating agent having an average particle diameter of not more than 50 μm, an organic compound containing a metal salt of a carboxyl group, and a polymer compound containing a metal salt of a carboxyl group, (b) from 3 to 30 parts by weight of modified polyolefin or modified olefin-based elastomer prepared by adding from 0.001 to 10 mol % of an alicyclic carboxylic acid containing a cis-double bond in the ring or its functional derivative to a polyolefin or olefin-based elastomer, (c) from 1 to 30 parts by weight of a copolymer comprising from 80 to 99 wt % of α-olefin, from 1 to 20 wt % of glycidyl methacrylate or glycidyl acrylate, and up to 19 wt % of vinyl acetate, (d) from 0.3 to 10 parts by weight of an ester-based plasticizer, and (e) up to 150 parts by weight of a fibrous reinforcing material.

Thermal recording material

Abstract: PURPOSE:To obtain excellent thermal sensitivity, by containing a specific compound in the thermal layer of a thermal recording material. CONSTITUTION:In a thermal recording material wherein a thermal layer capable of forming a color at the time of heating based on a color forming leuco dye, a phenolic compound and a binder is provided on a support, a compound represented by general formula (I) (wherein R1 is a hydrogen atom, a halogen atom, an 1-5C lower alkyl group, an alkoxy group or an alkoxycarbonyl group, m is 0 or 1 and n is 2-4. When n is 2, R2 is a divalent org. goup. When n is 3, R2 is a trivalent org. group and when n is 4, R2 is a tetravalent org. group) is contained in the thermal layer. As the color forming leuco dye, a triphenylmethane or fluorane leuco dye is designated. As a phenolic compound, a phenolic compound or phenolic resin, which is solid at ambient temp. and pref. has a m.p. of 70 deg.C or more is designated. As a binder, polyvinyl alcohol, methyl cellulose or a vinyl acetate copolymer emulsion are used. The thermal recording material is obtained by a method wherein the color forming leuco dye, the phenolic compound and the compound represented by general formula (I) are separately dispersed in an aqueous medium containing the binder and ground into particles to prepare dispersions which are, in turn, applied to the support and dried.

ESR studies on radical polymerization of vinyl ethers

Abstract: ESR studies on the radical polymerization of vinyl ethers were performed from −50°C to room temperature using di-tert-butylperoxide as a photoinitiator. Well resolved ESR spectra were assigned to propagating radicals of vinyl ethers. Their hyperfine splitting constants due to α-proton were about 16 G, being smaller than those of ethyl acrylate and vinyl acetate. The smaller constants is ascribed to a deviation of the propagating radicals from sp2 hybrid structure. The reason why high polymers are not obtained from vinyl ethers by radical polymerization is discussed on the basis of information from the ESR studies.

Effect of solvent for vinyl acetate polymerization on microstructure of poly(vinyl alcohol)

Abstract: The solution polymerization of vinyl acetate was carried out in several solvents at 0 to 100°C, using 2,2′-azobisisobutyronitrile as initiator. For the resulting poly(vinyl alcohol) (PVA), iodinecoloration, 1,2-glycol structure and tacticity were observed. The pentad tacticity of PVA was estimated from its methine carbon spectra by means of 13C-FTNMR spectrometer. Iodine-coloration ability of PVA varied markedly with the type of polymerization solvent and decreased in the following order: phenol > aq. phenol > methyl alcohol > ethyl acetate > DMSO, ethylene carbonate. The syndiotactic fraction in PVA also decreased with polymerization solvent in the same order as that of iodine coloration, while 1,2-glycol content of PVA was not almost affected by polymerization solvent except for phenol and aq. phenol. In solution polymerization performed, effect of polymerization temperature on tacticity was less than that of solvent.

Nonadsorptive hydrophilic membrane

Abstract: PURPOSE:To obtain the titled hydrophilic membrane which excels in water permeability and retentivity and stain resistance and can be used continuously and repeatedly and can be easily handled, by graft-polymerizing a monomer having a neutral OH group with a porous membrane obtained from, e.g., a polyolefin. CONSTITUTION:A graft-polymerizable monomer having at least one neutral OH group or a functional group as its precursor (e.g., allyl alcohol or vinyl acetate) is graft-polymerized with a hydrophobic porous membrane obtained from a polyolefin, an olefin/halogenated olefin copolymer, polyvinylidene fluoride or the like to obtain the titled hydrophilic membrane having a three-dimensional network structure and a neutral OH group content of 0.1-5 meq per g of the membrane and being in the form of a flat film, a tube, especially, a hollow yarn of an inside diameter of 0.1-10mm and a thickness of 0.05-5mm.

Synthesis and characterization of fluorescently labelled poly(vinyl acetate) particles

Abstract: Nonaqueous dispersions of poly(vinyl acetate) particles stabilized with poly(2-ethylhexyl methacrylate) and labelled with fluorescent dyes in the core and stabilizer polymer phases were prepared. The materials were characterized using a broad range of techniques (NMR, UV, and fluorescence spectroscopy. GPC, particle sizing, and DSC). The data show that dispersion polymerization of vinyl acetate in the presence of stabilizers containing certain fluorescent dye derivatives, instead of unlabelled stabilizer, results in changes in the mean particle size, size distribution, composition, and molecular weights of the colloidal polymer particles. It was found that increasing the amounts of fluorescent groups in the stabilizer resulted in smaller mean particle sizes and larger amounts of irreversibly attached stabilizer. When the average number of labels in stabilizer exceeded one per chain, a new ultra-high molecular weight polymer fraction appeared. The fluorescence spectra for several of these materials are reported. We describe how fluorescence decay curves can be used to assess block formation and local phase separation in particles labelled with phenanthrene groups. These materials are intended to be used for more detailed studies by fluorescence spectroscopy. Those results will be published in due course.

Use of ethylene terpolymers as additives for mineral distillates oils and mineral oil

Abstract: 1. The use of terpolymers with an average molecular mass of 500 to 10,000 g x mol**-1, which, in addition to ethylene, contain 0.5 to 20 wt. % diisobutylene and 20 to 35 wt. % vinyl acetate (in each case related to the terpolymer) and which per 100 CH2 groups exhibit 6 to 20 CH3 groups in the side chains, which do not originate from the vinyl acetate, as additives for mineral oils and mineral oil distillates.

Fluorescence studies of polymer blends: Anchoring stabilizer chain in non‐aqueous dispersions

Abstract: Non-aqueous dispersions of poly(vinyl acetate) stabilized by a surface layer of poly(2-ethylhexyl methacrylate) (PEHMA) were prepared. We modified the recipe for particle synthesis, using as a stabilizer a copolymer of EHMA containing a small amount of either phenanthrene (Phe) or pyrene (Py) groups. These fluorescent labels permit us to assess different aspects of stabilizer chain morphology and dynamics. In the particles labeled with Phe groups, the ability of oxygen to quench Phe fluorescence is used as a monitor of O2 sorption at the stabilizer-particle interface. In these experiments, information about the location of the labels and the PEHMA polymer is obtained. In the particles labeled with Py, pyrene self-quenching and excimer formation serves as a sensor of conformational and mobility changes in the PEHMA polymer upon anchoring in the particle.

A dielectric study of poly(ethylene‐co‐vinyl acetate)–poly(vinyl chloride) blends. II. Loss curve broadening and correlation parameters

Abstract: Normalized dielectric loss curves for blends of PVC with an EVA copolymer containing 70% vinyl acetate showed significant broadening with increasing PVC content. In conjunction with phase separation studies it was concluded that increasing loss curve broadness correlated with increasing tendency toward phase separation. Calculation of correlation parameters for the blends revealed differences in intermolecular correlations with blend composition.

Small particle size latex based on vinyl acetate polymers

Abstract: Colloid-free vinyl acetate latexes having an average particle size between 400 Å to 700 Å at a concentration of 30 to 50% by weight have been prepared The latexes comprise 60 to 100 weight parts of vinyl acetate monomer with about 40 to 0 weight parts of one or more ethylenically unsaturated comonomers such that the glass transition temperature of the polymers are between -10° and 40° C The latexes are prepared by emulsion polymerization in aqueous medium, in the presence of 005 to 20 parts of an anionic surfactant, eg, alpha-olefin surfactant, and 005 to 15 parts of an ionic comonomer, eg, sodium 2-acrylamido-2-methylpropane sulfonate (Na-AMPS) The interior wall primer-sealer derived from these fine particle size vinyl acetate latexes showed excellent enamel hold-out properties and paint stability The latexes may also be applied aas binders in the manufacture of other paints, adhesives, papers, and as textile sizes

Miscibility of mixtures from partially hydrolyzed poly(vinyl acetate) and poly(N‐vinyl‐2‐pyrrolidone)

Abstract: Polymers with different compositions of vinyl alcohol and vinyl acetate units (P(VA-VAc)), obtained by alcoholysis of poly(vinyl acetate) with sodium methoxide, were mixed with poly(N-vinyl-2-pyrrolidone) (PVP). The miscibility was studied observing glass transition temperatures by differential scanning calorimetry (DSC). The calorimetric results indicate that for vinyl alcohol unit contents in P(VA-VAc) of roughly 70 wt.-% or more, P(VA-VAc)/PVP blends are fully miscible, whereas blends obtained from P(VA-VAc) with vinyl alcohol contents lower than the above mentioned values are only partially miscible or even immiscible. The miscibility is attributed to hydrogen bond interactions between hydroxyl groups in P(VA-VAc) and the carbonyl group of PVP.

The volumetric behaviour of poly(vinyl alcohol) in aqueous solution

Abstract: High-precision density measurements of aqueous solutions of a narrow molecular mass fraction of poly(vinyl alcohol) prepared by 80% alcoholysis of poly(vinyl acetate), over an extended range of concentration and temperature, have revealed a complex pattern of solution behaviour. The concentration dependence of the partial molal volume and apparent molal expansibility indicate that two processes occur in solution; a conformational change at low concentrations (ca. 0.05% w/w) and an aggregation at higher concentrations (ca. 0.2% w/w). The concentration at which these processes occur varies with temperature showing a minimum in the region 14–18 °C. The volumetric data presented suggest that the temperature dependence of these two processes is a function of the solvent–solvent interactions and the minimum at 14–18 °C reflects a critical region for water over this temperature range.

Trail addition of acrylamidobutyraldehyde dialkyl acetal-type monomers during the polymerization of vinyl acetate copolymer binders

Abstract: In a process for preparing a nonwoven binder emulsion containing a crosslinkable vinyl acetate or vinyl acetate/ethylene copolymer prepared by polymerizing in an aqueous dispersion vinyl acetate or vinyl acetate and ethylene with a crosslinkable comonomer of formula I R--NH--(CHsub2)subn --CH(ORsup1)sub2 (I) wherein R is a C 3 -C 10 olefinically unsaturated radical having functionality which renders the nitrogen atom electron deficient, the olefinic unsaturation functionality being polymerizable, R 1 is hydrogen or a C 1 -C 4 alkyl group and n is 3 or 4, the method for improving the wet tensiles of such copolymer which comprises (1) polymerizing vinyl acetate in an aqueous dispersion reaction medium, optionally under an ethylene pressure, (2) commencing the addition of 05 to 15 wt % of a crosslinkable comonomer of formula I to the reaction mixture when about 50-80% of the total vinyl acetate in the polymerization recipe has been polymerized, and (3) completing addition of the crosslinkable comonomer after the completion of the addition of the vinyl acetate to the reaction mixture and substantially with the finishing of vinyl acetate polymerization, ie when the free vinyl acetate content of the reaction medium is from 05 to 4 wt %