Showing papers on "Vinyl acetate published in 1973"

A kinetic study of the emulsion polymerization of vinyl acetate

Abstract: The emulsion polymerization of vinyl acetate was studied at 50°C. It was found that the rate of polymerization was proportional to the 0.5 power of the initiator concentration and the 0.25 power of the number of particles. The number of particles was proportional to the power 0.5 ± 0.05 of the emulsifier concentration, but independent of the initiator concentration. The limiting viscosity number of the polymers produced was independent of the initiator concentration and number of polymer particles. It is suggested that the mechanism of vinyl acetate emulsion polymerization is similar to that of vinyl chloride. The linearity of the conversion-versus-time curve is explained as being due partly to a decrease in the desorption rate of radicals from the polymer particles and partly to a decrease in the termination rate constant.

Thermal stability of glucose oxidase and its admixtures with synthetic polymers.

Abstract: The thermal stability of glucose oxidase in solution was studied as a function of time and temperature between 37–60°C. As expected, the rate of thermal inactivation increased with temperature and at 60°C more than 80% of the enzyme's activity was lost after 0.5 hr incubation. Similar stability measurements on enzyme solutions containing water soluble synthetic polymers showed that several of the polymers significantly enhanced the thermal stability of glucose oxidase. Copolymers of vinyl acetate with either vinyl pyrrolidone or vinyl alcohol were found to be particularly effective. The molecular weight of the added polymers was found to be unimportant in the stabilization process but both polymer concentration and compositions were shown to be critical parameters.

Adhesive composition consisting of polyvinylalcohol solution or polyvinylacetate latex modified with hydrophobic solution of isocyanate compound

Abstract: An adhesive composition is provided comprising (1) a member selected from the group consisting of an aqueous solution of polyvinylalcohol, an aqueous emulsion of vinyl acetate polymer and an aqueous latex of butadiene polymer and (2) a hydrophobic solution of an isocyanate compound or polymer.

Well completion and workover fluid

Abstract: A non-damaging well completion and workover fluid comprising a dispersion of finely divided, slowly oil-soluble, water-insoluble solid particles in an aqueous salt solution containing chrome lignite, hydroxyethyl cellulose and xanthan gum. The density of the fluid is controlled by varying the concentration of salt dissolved in the solution. The finely divided solid particles consist of a homogeneous solid solution of (1) wax; (2) an oil-soluble surface active glyceryl or sorbitan partial ester of a saturated higher fatty acid; (3) a water-dispersible surface active polyethylene glycol monoester of a saturated higher fatty acid; (4) an ethylene/vinyl acetate copolymer, and (5) a fatty alcohol.

Modulus reinforcement in elastomer composites. II. Polymeric fillers

Abstract: Blends were prepared with high-modulus “filler polymers,” polystyrene, polyamide, and poly(methyl methacrylate) dispersed in a low modulus matrix of ethylene/vinyl acetate copolymer. The modified Kerner equation was applied to dynamic mechanical data obtained on these blends, which may be considered to be model systems for thermoplastic elastomer block polymers. The implication of the interaction parameter, B, in terms of the reinforcing capability of each polymer as well as its optimum volume fraction in the blend, is discussed.

Process for the preparation of a dispersible vinyl acetate/ethylene polymer powder

Abstract: Vinyl acetate/ethylene copolymer powders are obtained by spraydrying of the corresponding aqueous polymer dispersions while simultaneously adding finely divided inorganic materials as anticaking agents. The polymer powders thus obtained have an excellent storage stability, are easily dispersible in water and yield plastics mortars of high water resistance and plasterings made therefrom which are free from cracks.

Process of stabilizing soil and soil additive product

Abstract: A soil additive comprising a vinyl acetate homopolymer emulsion which includes vinyl acetate, hydroxyethyl cellulose, a nonatonic ethoxylated surfactant, potassium persulfate, sodium bicarbonate and water; a polyvinyl alcohol mixture which includes water, hydrogen peroxide, glycerin and polyvinyl alcohol; and a water repellent emulsion which comprises paraffin wax, an ethoxylated surfactant, diglycol stearate, candelilla wax, stearic acid, water, zirconium acetate, and ethylene urea resin. A process of injecting the additive into the soil is disclosed.

Sealing and briquetting finely divided material with vinyl copolymer and wax

Abstract: An ethylene/vinyl acetate resin copolymer mixed with paraffin wax coats and binds finely divided materials compressed into a briquette for addition to molten metal. The binder, which forms a minor portion of the total briquette, may be extended by first coating one of the finely divided materials intended for incorporation in the briquette whereby a very small percentage of the binder is thoroughly and evenly distributed throughout the briquette.

Manufacture of an electrostatic toner material

Abstract: An electrostatic toner material for use in electrophotography consisting essentially of finely divided particles formed of a generally uniform mixture comprised of 5 to 15 % by weight of a colored material and 95 to 85 % by weight of resin mixture consisting essentially of: A. 40 to 60 % by weight of a polymer having at least 50% of the recurring units thereof constituted by at least one styrene monomer of the formula: ##EQU1## wherein R is hydrogen or methyl, and the balance of such recurring units derived from at least one alkyl methacrylate monomer wherein alkyl comprises 1-4 carbon atoms, B. 20 to 40 % by weight of a homopolymer of butyl acrylate or butyl methacrylate, or copolymers thereof with up to 80 % by weight of methyl acrylate or methyl methacrylate, and C. 5 to 20 % by weight of a polymeric plasticizer selected from polyvinyl butyral, polyethylene and co(vinyl acetate/ethylene). The electrostatic toner material consists of particles having a diameter between 1 and 30 microns.

Method for inhibiting transmission of airborne noise

Abstract: It has been found that transmission of airborne noise can be inhibited by interposing in the air space between the noise source and the location to be insulated a thin, dense, normally self supporting film or sheet composed essentially of certain ethylene-vinyl acetate copolymers and from about 60 to about 90 percent by weight of inorganic filler materials effective to produce an overall density greater than at least 2 grams per cubic centimeter. The average vinyl acetate content of the ethylene-vinyl acetate copolymer, preferably a mixture or blend of copolymers, must be in the range of from about 10 to about 42 percent by weight of the copolymer ingredient. The normally selfsupporting film or sheet gives a level of sound blocking greater than that expected from calculations according to the Mass Action Law (sometimes referred to as Berger''s Law.

Studies of polymer blends. I. Compatibility of poly(vinyl chloride) and poly(ethylene‐co‐vinyl acetate‐co‐sulfur dioxide)

Abstract: Various methods of determining polymeric molecular compatibility were applied to blends of poly(vinyl chloride) (PVC) and poly(ethylene-co-vinyl acetate-co-sulfur dioxide) (E/VA/SO2). In one series, where the E/VA/SO2 had a mole composition of 72.7/18.5/8.8, true compatible blends were demonstrated by phase-contrast microscopy, torsion pendulum studies, and differential scanning calorimetry experiments for blends containing up to 40% E/VA/SO2. These blends exhibited a single Tg whose compositional variation was found to follow the Fox expression. Experimental densities were slightly greater than predicted on assuming volume additivity. This observation implies better packing and a negative heat of mixing and thus is in harmony with a negative free energy of mixing and the observed molecular compatibility.

Carbon-13 Nuclear Magnetic Resonance Spectroscopy of Poly(vinyl acetate) and Poly(vinyl alcohol)

Abstract: The carbon-13 high resolution nuclear magnetic resonance spectra with proton spin decoupling have been obtained for poly(vinyl acetate) and poly(vinyl alcohol). Carbon-13 resonances of the skeletal carbons of poly (vinyl acetate) are more sensitive to the steric configuration than those of the side-chain carbons. The spectra of α-methine carbons of poly(vinyl alcohol) have clear splits corresponding to triad and (partially) to pentad placements. By comparing the results of carbon-13 spectra with those of proton spectra, it was confirmed that the nuclear Overhauser effect due to the proton decoupling has no influence on the estimation of microtacticity through the relative intensities of peaks in the carbon-13 spectra.It was shown that the detection and estimation of the branches in poly(vinyl alcohol) might be possible by using the carbon-13 resonance.

A kinetic model of persulfate–bisulfite‐initiated acrylonitrile polymerization

Abstract: The molecular weight distribution has been derived for a homopolymer polymerized in a continuous-feed reactor under homogeneous conditions. The derived equations are then compared with data obtained on polymers of acrylonitrile–co(vinyl acetate) prepared under heterogeneous conditions with the potassium peroxydisulfate–sodium bisulfite–iron redox system. The termination reaction is assumed to be effected completely by recombination of active radicals with no disproportionation. The only transfer reaction considered is the transfer-to-activator reaction The transfer and termination reactions produce polymers with different acid groups as endgroups. Each molecule, on the average, contains one sulfonate group, whereas the concentration of sulfate groups depends upon the extent of the transfer-to-activator reaction. The basic dye acceptance of the polymer depends on the number of acid groups in the polymer and hence on the activator and catalyst concentrations. Analysis of the basic dye acceptance and conversion data at a variety of catalyst and activator concentrations yields the following parameters at 50°C: kp/k = 1.01 (1./mole sec)1/2, ktr/kp = 0.2063, and k1 [see eq. (1)] = 50.7 l./mole sec. Owing to the heterogeneous nature of the polymerization, the weight-average molecular weight of the polymer depends only on the activator concentration and the conversion and not directly on the catalyst concentration as predicted.

Organometallic polymers. XXIV. Radical‐initiated copolymerization of ferrocenylmethyl acrylate and methacrylate with acrylonitrile, maleic anhydride, and N‐vinyl‐2‐pyrrolidone

Abstract: Ferrocenylmethyl acrylate (I) and ferrocenylmethyl methacrylate (II) have been readily copolymerized with maleic anhydride in benzene–ethyl acetate solutions. Similarly, II has been copolymerized with both acrylonitrile and N-vinyl-2-pyrrolidone in benzene solutions to give higher molecular weight copolymers in high yields. In all cases azobisisobutyronitrile has been the initiator. Based on e values obtained, the metal carbonyl substituent acts as an electron-withdrawing group. Over a wide range of comonomers (N-vinyl-2-pyrrolidone, styrene, vinyl acetate, methyl acrylate, acrylonitrile, and maleic anhydride) I and II exhibit r1 values lower than (and r2 values higher than) similar copolymerizations with methyl acrylate or methyl methacrylate. Further more, the Q values found for I (0.03–0.11) and II (0.08–0.18) are smaller than those for methyl acrylate (0.46) and methyl methacrylate (0.74). Thus, I and II are less reactive than expected, presumably due to steric effects.

Carpet backsized with hot melt adhesive and method

Abstract: Hot melt compositions containing copolymer of ethylene and vinyl acetate and/or alkyl acrylate wherein the alkyl group contains 1-18 carbon atoms; ester of rosin and polyhydric alcohol; and ester of polyhydric alcohol and dimer and/or trimer of fatty acid are particularly useful as carpet backing adhesives

Thermodynamics of concentrated polymer solutions containing polyethylene, polyisobutylene, and copolymers of ethylene with vinyl acetate and propylene

Abstract: Gas-liquid chromatography is used to measure polymer-solvent interactions in polymer solutions where the solvent is at infinite dilution. Experimental data are presented for 24 binary polymer-solvent systems in the temperature range 50° to 150°C. A simple relation exists between the experimental retention volume data and the infinite dilution volatility; this volatility can be used to calculate the solvent vapor pressure over the polymer solution up to about 0.1 weight fraction solvent. Using concepts from the Prigogine-Flory theory of polymer solutions, Flory-Huggins X parameters for some polymer-hydrocarbon systems were correlated with the hydrocarbon's normal boiling temperature.

Organometallic Polymers. XXVII. Radical-Initiated Polymerization and Copolymerization of π-(2, 4-Hexadien-1-yl Acrylate) tricarbonyliron

Abstract: The novel monomer, π-(2, 4-hexadiene- l-yl acrylate) tricarbonyliron (HATI), has been prepared by two routes. It was homopolymerized and copolymerized with acrylonitrile, vinyl acetate, styrene, and methyl acrylate in benzene solutions. In all cases azobisisobutyronitrile was the initiator. The relative reactivity ratios, where HATI is defined as M1, were determined: r1 = 0.34, r2 = 0.74, M2 = acrylonitrile; r1 = 2.0, r2 = 0.05, M2 = 0.74, M2 = acrylonitrile; r1 = 2.0, r2 = 0.05, M2 = vinyl acetate; r1 = 0.26, r2 = 1.81, M2 = styrene; and r1 = 0.30, r2 = 0.74, M2 = methyl acrylate. The homo-and copolymers had high values of Tg. When polymerizations are carried out at high concentrations, a very high molecular weight tail is observed in HATI hompolymerizations and in HATI-methyl acrylate copolymerizations. The polymers were characterized by IR, gel permeation chromatography, viscosity, and differential scanning calorimetry studies. Finally, thermal decompositions carried out in air resulted in dec...

Metal foil-plastic laminate and method of preparing the same

Abstract: A metal foil-plastic laminate comprising an upper layer of a member selected from the group consisting of a polyethylene-vinyl acetate and ethylene-vinyl acetate copolymer containing no more than 8 wt % of vinyl acetate and a lower layer of an ethylene-vinyl acetate copolymer containing 10-45 wt % of vinyl acetate, thermally pressed on at least one surface of a metal foil, said lower layer being in contact with the metal foil and method for preparing the same

Heterotactic poly(vinyl alcohol)

Abstract: Bulky substituents in vinyl trialkylsilyl ethers and vinyl trialkylcarbinyl ethers led to heterotactic polymers (H = 66%). The polymers were converted into poly(vinyl alcohol) (PVA) and further to poly(vinyl acetate), and tacticity was determined as poly(vinyl acetate). Vinyl triisopropylsilyl ether in nonpolar solvents yielded a heterotactic polymer with a higher percentage of isotactic triads than syndiotactic triads (Hetero-I). Vinyl trialkylcarbinyl ethers in polar solvents gave a heterotactic polymer with more syndiotactic triads than isotactic (Hetero-II). Heterotactic PVA was soluble in water and showed characteristics infrared absorptions. Interestingly, Hetero-I PVA showed no iodine color reaction, but Hetero-II showed a much more intense color reaction than a commercial PVA. The mechanism of heterotactic propagation was discussed in terms of the Markov chain model.

Chemically opening chrysotile asbestos and encapsulating

Abstract: Chrysotile asbestos is chemically opened into the individual fibrils by soluble vinylic polymer polyelectrolytes containing carboxylic acid groups in aqueous media Polyacrylic acids, polymethacrylic acids, maleic anhydride polymers and water-soluble copolymers thereof are preferred polyelectrolytes and form stable colloidal dispersions The polyelectrolytes are neutralized to alkaline pH with inorganic or organic bases, but preferably with basic vinylic monomers when complete encapsulation is desired By a further aspect of the invention the polyelectrolyte-coated fibrils in aqueous dispersion are encapsulated by copolymerization with (a) a basic vinylic comonomer (used for pH control) such as dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate or a vinylpyridine; and (b) a non-basic vinylic comonomer such as styrene, divinylbenzene, vinyl chloride or fluoride, vinyl acetate, methyl methacrylate, ethyl acrylate, acrylonitrile, and methacrylonitrile The encapsulated fibrils are advantageous for forming reinforced composites including laminates and foamed or cellular products

Charge Transfer Complexes. Competition between Donor and Solvent for the Acceptor. A New Method of Study. Case of Maleic Anhydride and Vinyl Monomers: Styrene and Vinyl Acetate

Abstract: Charge transfer complexes between maleic anhydride and vinyl monomers have been investigated by using UV absorption techniques. A short review of the application of this technique to our problem has been made. Starting from the assumptions assumed by Merrefieid and co-workers, we have developed a new method of taking account of the possibility of complexation between the acceptor and the solvent.

Photopolymerization of Styrene in the Presence of Oxygen. Role of the Charge-Transfer Complex

Abstract: Ultraviolet absorption spectra of several monomers such as styrene, α-methylstyrene, isoprene, vinyl acetate, etc., were measured in nitrogen and oxygen atmospheres by bubbling the respective gases into the monomers at room temperature. The extra absorptions due to the oxygen which could be ascribed to contact charge-transfer complexes between monomers and oxygen with oxygen as an electron acceptor was found. The photopolymerization of styrene was carried out to investigate the role of the charge-transfer complex in it and was found to proceed several orders of magnitude faster in the presence of small amounts of oxygen than in its abscence. On the basis of polymer composition, viscosity measurement, the wavelength dependence of polymerization, and the ability of initial product to initiate polymerization, these facts could be explained as follows. Polystyrene peroxide is formed by photoirradiation of the charge-transfer complex between styrene and oxygen in the initial stage of the polymerization and the photoinduced decomposition of the polystyrene peroxide initiates the polymerization of the styrene. Some contribution from the exciplex between oxygen and excited singlet styrene to the formation of the alternating copolymer was also suggested on the basis of measurements of the fluorescence spectra of styrene.

Glass fiber sizing composition and resultant product with high resistance to abrasion

Abstract: 1. AN AQUEOUS GLASS SIZING COMPOSITION FOR FILAMENT GLASS FIBERS WHICH CONSISTS ESSENTIALLY OF 0.5 TO 15 WEIGHT PERCENT OF POLY(VINYL ACETATE); 0.1 TO 5 PERCENT OF A POLYETHYLENE GLYCOL HAVING A MOLECULAR WEIGHT IN THE RANGE OF 200 TO 6000; 0.01 TO 0.6 WEIGHT PERCENT OF A POLYESTER COMPATIBLE METHACRYLIC SILANE; 0.01 TO 1.0 PERCENT OF A CATIONIC ALKYL AMIDE REACTION PRODUCT OF A C5 TO C20 ALKYL CARBOXYLIC ACID AND AN ETHYLENE AMINE, AND THE BALANCE DE-IONIZED WATER, THE COMPOSITION HAVING A PH OF NOT GREATER THAN 6 AND A SOLIDS CONTENT IN THE RANGE OF 1-22 PERCENT.

Vinyl chloride graft polymers and process for preparation thereof

Abstract: A graft copolymer is described which contains, by weight, from about 60% to 95% of polymerized vinyl chloride and from 5% to 40% of an ethylene/vinyl acetate copolymer backbone which, in turn, contains from 10% to 40%, by weight, of polymerized vinyl acetate. This graft copolymer is thermally stable and has both good physical properties and vastly improved processing characteristics, particularly for injection molding operations. The copolymer is prepared in aqueous suspension at polymerization temperatures ranging from 90* C to 165* C employing a suitable, monomer-soluble, free-radical type initiator which is injected into the reaction mixture at a prescribed rate throughout the reaction.

Organic Phosphorus Compounds 60. The direct synthesis of tris(N‐substituted carbamoylethyl) phosphine oxides

Abstract: The reaction of elemental white phosphorus with N-alkyl acrylamides and N,N-dialkyl acrylamides in the presence of a base is described and the physical properties of 8 new tertiary phosphine oxides of general formula (R2NCOCH2CH2)3PO (R = H, CH3, C2H5,(CH2)4, (CH2)5, and C2H4OC2H4, CH2CHCH2) are reported. Interaction of white phosphorus with RNCS, RNCO, azo-bis-isobutyronitrile, Ph2NNPh2, vinyl acetate, vinyl ethyl ether, and expoxides has also been investigated.