Emulsion polymerization alkyl acrylates

Ferguson, R, Sherrington, D.C. and Gough, A. (1993) Preparation, characterization and use in emulsion polymerization of acrylated alkyl ethoxylate surface-active monomers. Polymer, 34, 3281-92. 

The surfactants used in the emulsion polymerization of acrylic monomers are classified as anionic, cationic, or nonionic. Anionic surfactants, such as salts of alkyl sulfates and alkylarene sulfates and phosphates, or nonionic surfactants, such as alkyl or aryl polyoxyethylenes, are most common (87,98—101). Mixed anionic—nonionic surfactant systems are also widely utilized (102—105). 

Polymers of lower n-alkyl acrylates are used in plastics to only a limited extent. Ethyl and butyl acrylates are, however, major components of acrylic elastomers. The polymers are usually formed by free-radical emulsion polymerization. Because acrylate esters are sensitive to hydrolysis under basic conditions, the polymerizations are usually conducted at neutral or acidic pH. The acrylic rubbers, like other elastomers, must be crosslinked or vulcanized to obtain optimum properties. Crosslinking can be accomplished by reactions with peroxides through abstractions of tertiary hydrogens by free radicals ... 

The free radical initiators are more suitable for the monomers having electron-withdrawing substituents directed to the ethylene nucleus. The monomers having electron-supplying groups can be polymerized better with the ionic initiators. The water solubility of the monomer is another important consideration. Highly water-soluble (relatively polar) monomers are not suitable for the emulsion polymerization process since most of the monomer polymerizes within the continuous medium, The detailed emulsion polymerization procedures for various monomers, including styrene [59-64], butadiene [61,63,64], vinyl acetate [62,64], vinyl chloride [62,64,65], alkyl acrylates [61-63,65], alkyl methacrylates [62,64], chloroprene [63], and isoprene [61,63] are available in the literature. 

In the first stage, the elastomeric component, typically a poly-(alkyl acrylate) rubber, is produced. This reaction can be carried out either in a water-based emulsion or in a solution polymerization process. 

Acrylics. There are two principal classes of acrylic sealants latex acrylics and solvent-release actylics. High molecular weight latex acrylic polymers are prepared by emulsion polymerization of alkyl esters of acrylic acid, The emulsion polymers are compounded inlo sealants by adding fillers, plasticizers, freeze-thaw stabilizers, thickeners, and adhesion promoters. As is true of the silicone lalex sealants, die acrylic latex sealants are easy to apply and clean with water. 

Ferguson et al. [52] compared the behavior of a range of conventional alkyl ethoxylate surfactants in emulsion polymerizations with their acrylated analogues. This has allowed a direct comparison of identical surfactant structures, one of which remains kinetically mobile in the resultant lattices, while the other becomes chemically bound to the latex particles. The surfactants chosen for this study were C12 i4-(EO)30 with C12 14-(EO)30-A and C12 14-(EO)12 with C12 14-... 

Series I Acrylic Latex Emulsions. A series of four acrylic latex emulsions varying in glass transition temperature (Tg) (3) were applied first. Tg is the temperature at which the resin changes from a relatively flexible to a relatively stiff material. The acrylic latexes are made from water-insoluble monomers such as acrylates and alkyl acrylates polymerized in emulsion form to produce an aqueous dispersion or latex of the polymer. Upon drying, the emulsion is irreversibly broken so that the applied material becomes wash-fast. The application requires no catalyst or high temperature heating. 

The present paper is devoted to the investigation of emulsion polymerization of lower alkyl acrylates in... 

In the study of emulsion polymerization kinetics which depend on monomer polarity, the homologous scries of alkyl acrylates and alky] methacrylates are usually used because of thcir wide ranges of solubility in... 

Other authors observed that acrylic esters showed smaller gel effects, the larger the alkyl groups linked. According to Melville (25, 26), butyl acrylate polymerized in bulk shows no gel effect. If one assumes that EA shows no gel effect (at least under our conditions of y-emulsion polymerization), and that the pure monomer phase disappears at the maximum of Ubf, then the behavior of our system harmonizes well with theory after the maximum, the overnall reaction rate must decrease following first order with respect to [M],... 

The highly hydrophobic alkyd resin can serve as both reactant and coemulsifier (hydrophobe) in the mini-emulsion polymerization of alkyl (meth)acrylates [80, 110]. The strong synergism in the minidroplet nucleation was observed when highly hydrophobic unsaturated alkyd resin was used as the hydrophobe (>20 wt %). This feature is very different from the conventional coemulsifiers, such as long-chain alkanes and alcohols, that are effective around at 2 to 4%. 

A number of copolymers are known where vinyl acetate is the major component. In coatings, vinyl acetate is often used in copolymers with alkyl acrylates (line 2-ethylhexyl acrylate) or with esters of maleic or fumaric acids. Such copolymers typically contain 50-20% by weight of the comonomer and are usually formed by emulsion polymerization in batch processes. They are used extensively as vehicles for emulsion paints. 

Synonyms PEG-34 nonyl phenyl ether POE (34) nonyl phenyl ether Classification Ethoxylated alkyl phenol Properties Nonionic Toxicology TSCA listed Uses Surfactant, emulsifier for emulsion polymerization (acrylics and vinyl acetate), paints and coatings emulsifier in mfg. of food-contact articles... 

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