Polyvinyl acetate latex

Acrylonitrile/butadiene/styrene copolymer Ethyl acrylate binder, nonwoven fabrics AcrylatesA/A copolymer 2-Hydroxyethyl methacrylate Natural rubber latex Polyvinyl acetate... 

Chicle gum (Sapodilla tree latex), polyvinyl acetate, other natural latex s, including jelutong and rubber latex, filler (calcium carbonate)... 

At RT or elevated temperature, which ever is the recommended procedure) (or post-cure needed.) At RT P/F and R/F Solvent bonding of certain plastics materials Nitrile phenolics Acrylics with polymer dissolved in monomer but without accelerator Casein and casein-latex Polyvinyl acetate... 

Rubber latex. Polyvinyl Acetate (PVA), Casein, Acrylic. 

A bond coat of a polymer latex (also called polymer emulsions or dispersions) such as styrene butadiene (SBR), polyvinyl acetate (PVA) acrylics or modified acrylics. These are applied to the prepared concrete as... 

Polyvinyl acetate is an ingredient in white glue. It is a copolymer with vinyl alcohol in latex paints. 

This molecule is a copolymer with polymethyl methacrylate (PMMA) in acrylic latex paints, where the hydrophobic PMMA is surrounded by hydrophilic polyvinyl acetate molecules. Such a suspension of a hydrophobic polymer wrapped in a hydrophilic polymer is called a latex. 

The determination of adsorption isotherms at liquid-solid interfaces involves a mass balance on the amount of polymer added to the dispersion, which requires the separation of the liquid phase from the particle phase. Centrifugation is often used for this separation, under the assumption that the adsorption-desorption equilibrium does not change during this process. Serum replacement (6) allows the separation of the liquid phase without assumptions as to the configuration of the adsorbed polymer molecules. This method has been used to determine the adsorption isotherms of anionic and nonionic emulsifiers on various types of latex particles (7,8). This paper describes the adsorption of fully and partially hydrolyzed PVA on different-size PS latex particles. PS latex was chosen over polyvinyl acetate (PVAc) latex because of its well-characterized surface PVAc latexes will be studied later. 

More than 65% of the acetic acid produced in the United States goes into vinyl acetate. Nearly all the vinyl acetate ends up as polyvinyl acetate, used to make plastics, latex paints, and adhesives. About 12% of acetic acid is converted to acetic anhydride that is mostly used to make cellulose acetate, the white stuff in cigarette filters. It is also used in the manufacture of plastic sheeting and film and in formulating lacquers. 

Latex. A milk-like fluid containing small particles of natural or synthetic rubber suspended in water. Synthetic latexes are made by carrying out a polymerization step in aqueous medium (an emulsion polymerization). Water-base paints are made from polyvinyl acetate latex created in this way. 

Uses Manufacture of polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride-acetate resins used particularly in latex paint paper coatings adhesives textile finishing safety glass interlayers. 

Acetic acid is an important industrial chemical. The reaction of acetic acid with hydroxyl-containing compounds, especially alcohols, results in the formation of acetate esters. The largest use of acetic acid is in the production ofvinyl acetate (Figure 1.1). Vinyl acetate can be produced through the reaction of acetylene and acetic acid. It is also produced from ethylene and acetic acid. Vinyl acetate is polymerized into polyvinyl acetate (PVA), which is used in the production of fibers, films, adhesives, and latex paints. 

Polyvinyl acetate polymers synthesized by emulsion polymerization168, show strikingly different behavior188,189). Figure 41 shows Dz as a function of Mw. For the low molecular weights, D2 decreases as expected but from Mw = 14 106 onwards Dz remains constant. The measured samples were products obtained at different extents of monomer conversion. The soap surrounding the latex particles was removed and the samples were dissolved in methanol and measured. The behavior of Dz in this system is understood by recalling that... 

A polyvinyl acetate latex prepared by semi-continuous polymerization at 55° using a polymethacrylic acid-nonylphenol-poly-ethoxylate phosphate ester emulsifier and sodium persulfate-sodium formaldehyde sulfoxylate initiator (23). The latex was cleaned by ion exchange and serum replacement using both Nuclepore and Pellicon membranes, and the cleaned latex and serum fractions were analyzed by conductometric titration. In addition, the dried films were extracted with water and organic solvents, and the extracts were analyzed by infrared spectroscopy and thermo-gravimetric analysis. 

The results showed that all batch polymerizations gave a two-peaked copolymer compositional distribution, a butyl acrylate-rich fraction, which varied according to the monomer ratio, and polyvinyl acetate. All starved semi-continuous polymerizations gave a single-peaked copolymer compositional distribution which corresponded to the monomer ratio. The latex particle sizes and type and concentration of surface groups were correlated with the conditions of polymerization. The stability of the latex to added electrolyte showed that particles were stabilized by both electrostatic and steric stabilization with the steric stabilization groups provided by surface hydrolysis of vinyl acetate units in the polymer chain. The extent of this surface hydrolysis was greater for the starved semi-continuous sample than for the batch sample. 

Surfactant Interactions in Polyvinyl Acetate and Poly (vinyl acetate-butyl acrylate) Latexes... 

Recent investigations have shown that the behavior and interactions of surfactants in a polyvinyl acetate latex are quite different and complex compared to that in a polystyrene latex (1, 2). Surfactant adsorption at the fairly polar vinyl acetate latex surface is generally weak (3,4) and at times shows a complex adsorption isotherm (2). Earlier work (5,6) has also shown that anionic surfactants adsorb on polyvinyl acetate, then slowly penetrate into the particle leading to the formation of a poly-electroyte type solubilized polymer-surfactant complex. Such a solubilization process is generally accompanied by an increase in viscosity. The first objective of this work is to better under-stand the effects of type and structure of surfactants on the solubilization phenomena in vinyl acetate and vinyl acetate-butyl acrylate copolymer latexes. 

It is well known (3,5,6) that sodium lauryl sulfate interacts with some polymers such as polyvinyl acetate causing solubilization of the insoluble polymer leading to an increase in viscosity. In Figure 3, viscosity of the homopolymer and 70/30 VA/BA at various NaLS/polymer ratio is shown. It is seen that the viscosity of the 2% latex dispersion increases with increase in NaLS/polymer ratio. Similar visoosity data for the 85/15 VA/BA was intermediate between the homopolymer and 70/30 VA/BA latexes. Surfactants that showed a normal saturation type adsorption behavior did not show any significant visoosity increase of the latex. 

Figure 8. Density and extinction profile in rapid density gradient centrifugation of a latex of polyvinyl acetate (c 5 mg L 1, N = 40.000 min 1, t — t0 = 40 min,...

Figure 10. Density of different polymer latex particles as a function of centrifugation time (N = 40.000 min 1) (Y ) polyvinyl acetate (%) poly(vinylacetate-co-ethylene) (A) polystyrene (X) poly( butadiene-co-styrene) (O) poly butadiene)...

Latex Shelf Life. The shelf life of seed I was greater than 6 months, but none of the latexes produced in the tubular reactor had a shelf life of more than a week. Initially, a thin liquid layer formed at the top. After several weeks, a solid layer formed in the bottom of the container. Despite the high levels of emulsifier used, the large polyvinyl acetate particles separated quickly. No studies were made to increase the shelf life. 

Many epoxy dispersions are compatible with most types of latex emulsions including acrylic, urethane, styrene butadiene, vinyl chloride, and polyvinyl acetate. The epoxy dispersion can be used as a modifier for these emulsions to alter handling and application characteristics such as emulsion rheology, foaming tendencies, pH sensitivity, wetting properties, and coating coalescence. They can also be reacted into the latex resin either by reacting the epoxy with a functionalized latex or by use of an epoxy with a coreactant. In this way adhesive systems can be formulated that are cured at room or elevated temperatures. 

In general, these groups of cellulose ethers have been used for their innate adhesive properties and to provide thickening to adhesive formulations. They are used for plywood adhesives, industrial adhesives, wallpaper paste, library paste, and latex adhesives. For example, methylcellulose is used in some adhesives as an additive to control viscosity, especially in the heat-cure phenol-formaldehyde glues and other hot-pressing adhesives. Hydroxyethylcellulose is used as an ingredient in polyvinyl acetate emulsions, where it acts as a thickener and protective colloid. 

Adsorption of Polyvinyl Alcohols by Polyvinyl Acetate Latex. 

---