Polyvinyl acetate emulsions

While unaffected by water, styrofoam is dissolved by many organic solvents and is unsuitable for high-temperature applications because its heat-distortion temperature is around 77°C. Molded styrofoam objects are produced commercially from expandable polystyrene beads, but this process does not appear attractive for laboratory applications because polyurethane foams are much easier to foam in place. However, extruded polystyrene foam is available in slabs and boards which may be sawed, carved, or sanded into desired shapes and may be cemented. It is generally undesirable to join expanded polystyrene parts with cements that contain solvents which will dissolve the plastic and thus cause collapse of the cellular structure. This excludes from use a large number of cements which contain volatile aromatic hydrocarbons, ketones, or esters. Some suitable cements are room-temperature-vulcanizing silicone rubber (see below) and solvent-free epoxy cements. When a strong bond is not necessary, polyvinyl-acetate emulsion (Elmer s Glue-All) will work. 

The major synthetic adhesives used for bonding wood include urea, phenol, and melamine formaldehyde resorcinol formaldehyde, phenol resorcinol, and polyvinyl acetate emulsions. More recently one-component, moisture cured polyurethane adhesives have become popular for bonding wood. Natural adhesives such as casein and animal glues are also often used for general-purpose wood bonding. Epoxies have been used for certain specialized wood joining applications such as when wood is bonded to metal substrates. 

Polyvinyl acetate emulsions for manual application in the production of adhesive bound books were examined for stability. It was found, among other things, that plasticized homopolymers had poor or moderate stability, while copolymer types showed very high stability. The addition of calcium carbonate and calcium acetate could improve the lasting qualities of unstable materials but had little effect on the very stable ones. The addition of these buffering agents made the adhesive less acid and less damaging to papers (6). 

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. 

Possible Effect of Charged End-groups. A possible reason for differences between samples might be the process used for polymerising the original polyvinyl acetate. Emulsion polymerisation is likely to introduce a proportion of ionic (sulphate or carboxyl) end-groups which would not be expected if bulk polymerisation with benzoyl peroxide had been used. An Antweller Microelectrophoresis apparatus was used to measure rates of electrophoresis of polyvinyl alcohols in solution in a pH 7.8 phosphate buffer. No significant difference was observed between... 

BURCO FINISH 55 is a 55% solids polyvinyl acetate emulsion for use in textile finishing as a hand builder. 

Chemical nature Non-ionic polyvinyl acetate emulsion Particle size 0.5 to 2 microns Appearance White, free flowing liquid... 

CNC PVA NS is polyvinyl acetate emulsion which is prepared especially for use on textiles where maximum whiteness initially and upon storage is a must. 

CNC PVA NS is dispersed in water at temperatures from 80F to 160F. Usually the polyvinyl acetate emulsion is added to the finishing bath first, but actually may be added after resins and softeners are in the mix. 

CNC SOFT XXX is exceptionally versatile as it is compatible with anionic, cationic or nonionic substances. It is compatible with resins, catalysts and optical bleaches also acrylic resins, polyvinyl acetate emulsions and starches. The product may be applied by padding or exhaust methods. 

ADHERE-TEX 1510 is a semi-permanent pressure sensitive adhesive which develops outstanding tack when the cast film is dried. The adhesive properties may be modified by dilution with water, thickening, or blending with other polymers such as TEX-WET 1089, a polyvinyl acetate emulsion. 

Chem-Firm. [Ivax Industries] Polyvinyl acetate emulsion nonreactive hand builder, bodying agent... 

Dur-O-Set . [Nat l. Starch Chem.] Polyvinyl acetate emulsions ot ethylene vinyl acetate copdymers finish-it%, sizing, stiffening agents fiv fabrics pigment binder. 

Glo Rez. [Glo-Tex] Polyvinyl acetate emulsion or melamine forrnaldehyde resin hand modifier. 

Quabond . [Rhone-POulenc/Textile Rubber] Polyvinyl acetate emulsion textile size and firiish pqier coating. 

Vult-Acet . [General Latex Chem.] Polyvinyl acetate emulsion latex for adhesives, coatings hand modifiers for textiles. 

Orcoset [Cyanic Dyestuffs] Polyvinyl acetate emulsion semidurable hand building finish for cellulosics and synthetics. 

More than half of vinyl acetate monomer is used in polyvinyl acetate emulsions and resins. The largest use of polyvinyl acetate emulsions is in adhesive emulsions. This is followed by use in copolymers to produce latex paints which have largely replaced solvent-based paints in developed countries. The adhesive emulsions are used in all types of consumer adhesives and glues used in the construction industry. 

Di- -butyl phthalate is used in many products that are made from plastic. It is also in products like white glues and carpenter s glues made from a plastic known as polyvinyl acetate emulsion. Di- -butyl phthalate is also used in some paints, furniture lacquer, and nail polish. When it is in anything, di- -butyl phthalate is at a higher level when that product is new. There is less in products that are old. Because di- -butyl phthalate may be in some toys, there is a concern that children chewing on such toys might be exposed. No measurements have yet been made to show whether children are exposed in this way. 

The most important use of di- -butyl phthalate is as a plasticizer (Cadogan and Howick 1992, 1996). Plasticizers are compounds that are added to other substances in order to make them softer and more flexible (Cadogan and Howick 1996). Di- -butyl phthalate appears to be primarily used as a plasticizer in polyvinyl acetate emulsion adhesives (white glues and carpenter s glues, see Pocius 1991) as a solvent for... 

Zivica, V., The Properties of Cement Paste with Admixture of Polyvinyl Acetate Emulsion, Bulletin RILEM, No. 28, pp. 121-128 (Sept. 1965)... 

J. M. Geist, S. V. Amagna and B. B. Mellor Improved portland cement mortars with polyvinyl acetate emulsions. Industrial and Engineering Chemistry Vol.45, No.4 (1953), pp.759-767. 

Chem. Descrip. Carboxylated polyvinyl acetate emulsion CAS 9003-20-7... 

Uses Defoamer for adhesives, water reducible industrial coatings, aciylic/ vinyl aciylic/polyvinyl acetate emulsion sterns Features Effective in aciylic-urethane clear coats Properties Nonionic 100% act. 

Uses Defoamer for latex paints, coatings and adhesives based on B/S, acrylic, polyvinyl acetate emulsion systems and monomer stripping of PVAc, PVA, and acrylic latex Features Low-vise. 

In the hot-melt type, two principal polymer types are used polyolefin and ethylene co-polymer based and polyester and polyamide type. In the solvent-based type, the most prominent are neoprene (polychloroprene)-based solvent and latex types, and polyvinyl acetate emulsions. For pressure-sensitive adhesives, the most favored are acrylic adhesives and butyl rubber/polyisobutylene types. 

Corey, A.E., et al.. Polyvinyl acetate emulsions and polyvinyl alcohol for adhesives (Chapter 28). Handbook of Adhesives (I. Skeist, ed.), 3rd ed.. Van Nostrand Reinhold, New York, 1990. 

Adhesives for paper-to-paper applications are made from polyvinyl acetate emulsions, with added plasticizers, or from vinyl acetate copolymers (notably Ethylene-vinyl acetate copolymers) with added polyvinyl alcohol to modify viscosity, flow and coating properties, remoistenability and the rate of formation of the adhesive bond. These... 

---