Emulsion polymerization acrylic monomers

Sodium laureth sulfate emulsifier, emulsion polymerization acrylic monomers... 

Calimulse EM-22 Calimulse L-22 Cal-imulse L-30 Calimulse L-50 surfactant, emulsion polymerization acrylic monomers Sodium tridecyl sulfate surfactant, emulsion polymerization acrylics... 

Aqueous dispersions of poly(vinyl acetate) and vinyl acetate-ethylene copolymers, homo- and copolymers of acrylic monomers, and styrene-butadiene copolymers are the most important types of polymer latexes today. Applications include paints, coatings, adhesives, paper manufacturing, leather manufacturing, textiles and other industries. In addition to emulsion polymerization, other aqueous free-radical polymerizations are applied on a large scale. In suspension polymerization a water-irnrniscible olefinic monomer is also polymerized. However, by contrast to emulsion polymerization a monomer-soluble initiator is employed, and usually no surfactant is added. Polymerization occurs in the monomer droplets, with kinetics similar to bulk polymerization. The particles obtained are much larger (>15 pm) than in emulsion polymerization, and they do not form stable latexes but precipitate during polymerization (Scheme 7.2). 

Uses DetergenL emulsifier, dispersant, wetting agent for laundry detergents, household and industrial cleaners, emulsions, dispersions, surf. treatmenL leather, pulp/paper, dyes and pigments, paints, building prods., emulsion polymerization (acrylic, vinyl, and styrene monomers) Properties Colorless clear or cloudy liq. sol. 10% in alcohols, aromatic hydrocarbons sp.gr. 0.98 vise. 90 mPa-s drop pt. 18 C solid, pt. 

Sodium laureth sulfate emulsifier, emulsion polymerization styrene monomers Lutensol TO 8 Lutensol T012 emulsifier, emulsion polymerization styrene-acrylics... 

Baytron M 3,4-Ethylene dioxythiophene monomer, emulsion polymerization Sodium allybxyhydroxypropyl sulfonate monomer, emulsion polymerization acrylic latex paints Sipomer WAM II... 

Uses Emulsifier in emulsion polymerization (acrylic esters, styrene and vinyl monomers), ester waxes and fatty acids stabilizer for emulsions, suspensions, and latexes... 

Uses Emulsifier for emulsion polymerization (acrylic esters, styrene and vinyl monomers)... 

Aerosol 18 Aerosol TR-70 BIO-SOFT D-40 Disponil SLS 2010 LIpolan PJ-400 Liponox NC-200 Monawet MT-70 POLYSTEP B-3 POLYSTEP B-24 POLYSTEP B-25 Rhodaoal LDS-22 Rhodapon TDS Sodium lauryl sulfate Sodium tridecyl sulfate Sunnol NP-2030 emulsifier, emulsion polymerization vinyl chloride/acrylics Liponox NC-200 Liponox NC-300 emulsifier, emulsion polymerization vinyl monomers Agnique OP-4070... 

Acrylates are primarily used to prepare emulsion and solution polymers. The emulsion polymerization process provides high yields of polymers in a form suitable for a variety of appHcations. Acrylate polymer emulsions were first used as coatings for leather in the eady 1930s and have found wide utiHty as coatings, finishes, and binders for leather, textiles, and paper. Acrylate emulsions are used in the preparation of both interior and exterior paints, door poHshes, and adhesives. Solution polymers of acrylates, frequentiy with minor concentrations of other monomers, are employed in the preparation of industrial coatings. Polymers of acryHc acid can be used as superabsorbents in disposable diapers, as well as in formulation of superior, reduced-phosphate-level detergents. 

Almost all synthetic binders are prepared by an emulsion polymerization process and are suppHed as latexes which consist of 48—52 wt % polymer dispersed in water (101). The largest-volume binder is styrene—butadiene copolymer [9003-55-8] (SBR) latex. Most SBRlatexes are carboxylated, ie, they contain copolymerized acidic monomers. Other latex binders are based on poly(vinyl acetate) [9003-20-7] and on polymers of acrylate esters. Poly(vinyl alcohol) is a water-soluble, synthetic biader which is prepared by the hydrolysis of poly(viayl acetate) (see Latex technology Vinyl polymers). 

Emulsion Polymerization. In this method, polymerization is initiated by a water-soluble catalyst, eg, a persulfate or a redox system, within the micelles formed by an emulsifying agent (11). The choice of the emulsifier is important because acrylates are readily hydrolyzed under basic conditions (11). As a consequence, the commonly used salts of fatty acids (soaps) are preferably substituted by salts of long-chain sulfonic acids, since they operate well under neutral and acid conditions (12). After polymerization is complete the excess monomer is steam-stripped, and the polymer is coagulated with a salt solution the cmmbs are washed, dried, and finally baled. 

It may also be possible to crosslink the acrylic PSA with the help of multifunctional acrylates or methacrylates [87], These monomers can simply be copolymerized with the balance of the other monomers to form a covalently crosslinked network in one step. Since the resulting polymer is no longer soluble, this typ)e of crosslinking is typically limited to bulk reactions carried out as an adhesive coating directly on the article or in emulsion polymerizations where the crosslinked particles can be dried to a PSA film. 

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. 

The soapless seeded emulsion copolymerization method was used for producing uniform microspheres prepared by the copolymerization of styrene with polar, functional monomers [115-117]. In this series, polysty-rene-polymethacrylic acid (PS/PMAAc), poly sty rene-polymethylmethacrylate-polymethacrylic acid (PS/ PMMA/PMAAc), polystyrene-polyhydroxyethylmeth-acrylate (PS/PHEMA), and polystyrene-polyacrylic acid (PS/PAAc) uniform copolymer microspheres were synthesized by applying a multistage soapless emulsion polymerization process. The composition and the average size of the uniform copolymer latices prepared by multistage soapless emulsion copolymerization are given in Table 11. 

Organic peroxide-aromatic tertiary amine system is a well-known organic redox system 1]. The typical examples are benzoyl peroxide(BPO)-N,N-dimethylani-line(DMA) and BPO-DMT(N,N-dimethyl-p-toluidine) systems. The binary initiation system has been used in vinyl polymerization in dental acrylic resins and composite resins [2] and in bone cement [3]. Many papers have reported the initiation reaction of these systems for several decades, but the initiation mechanism is still not unified and in controversy [4,5]. Another kind of organic redox system consists of organic hydroperoxide and an aromatic tertiary amine system such as cumene hydroperoxide(CHP)-DMT is used in anaerobic adhesives [6]. Much less attention has been paid to this redox system and its initiation mechanism. A water-soluble peroxide such as persulfate and amine systems have been used in industrial aqueous solution and emulsion polymerization [7-10], yet the initiation mechanism has not been proposed in detail until recently [5]. In order to clarify the structural effect of peroxides and amines including functional monomers containing an amino group, a polymerizable amine, on the redox-initiated polymerization of vinyl monomers and its initiation mechanism, a series of studies have been carried out in our laboratory. 

Polymerization, including radical polymerization, in supercritical C02 has been reviewed.1 6 137 It should be noted supercritical C()2 while a good solvent for many monomers is a very poor solvent for polymers such as the (meth)acrylates and S. As a consequence, with the exception of certain fluoropolymers and polymerizations taken to very low conversion, most polymerizations in supercritical CCb are of necessity precipitation, dispersion or emulsion polymerizations. 

A modified latex composition contains a phosphorus surface group. Such a latex is formed by emulsion polymerization of unsaturated synthetic monomers in the presence of a phosponate or a phosphate which is intimately bound to the surface of the latex. Thus, a modified latex containing 46% solids was prepared by emulsion polymerization of butadiene, styrene, acrylic acid-styrene seed latex, and a phosphonate comonomer in H20 in the presence of phosphated alkylphenol ethoxylate at 90°C. The modified latex is useful as a coating for substrates and as a binder in aqueous systems containing inorganic fillers employed in paper coatings, carpet backings, and wallboards [119]. 

Hydrophobic polymers with some hydrophilic groups can be obtained with an emulsion polymerization technique. Suitable monomers are nitrogen-containing acrylics and methacrylics allyl monomers such as dimethylamino-ethyl methacrylate, dimethylaminopropyl methacrylamide, diethylamino-ethyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate and nitrogen-containing allyl monomers (e.g., diallylamine and N,N-diallyl-cyclohexylamine) [225,226]. 

Erbil, H.Y., 2000, Vinyl Acetate Emulsion Polymerization and Copolymerization with Acrylic Monomers, CRC, Boca-Raton, FL. 

Bauer et al. describe the use of a noncontact probe coupled by fiber optics to an FT-Raman system to measure the percentage of dry extractibles and styrene monomer in a styrene/butadiene latex emulsion polymerization reaction using PLS models [201]. Elizalde et al. have examined the use of Raman spectroscopy to monitor the emulsion polymerization of n-butyl acrylate with methyl methacrylate under starved, or low monomer [202], and with high soUds-content [203] conditions. In both cases, models could be built to predict multiple properties, including solids content, residual monomer, and cumulative copolymer composition. Another study compared reaction calorimetry and Raman spectroscopy for monitoring n-butyl acrylate/methyl methacrylate and for vinyl acetate/butyl acrylate, under conditions of normal and instantaneous conversion [204], Both techniques performed well for normal conversion conditions and for overall conversion estimate, but Raman spectroscopy was better at estimating free monomer concentration and instantaneous conversion rate. However, the authors also point out that in certain situations, alternative techniques such as calorimetry can be cheaper, faster, and often easier to maintain accurate models for than Raman spectroscopy, hi a subsequent article, Elizalde et al. found that updating calibration models after... 

Emulsion Polymerizations, eg. vinyl acetate [VAc]/ABDA, VAc/ethylene [VAE]/ABDA, butyl acrylate [BA]/ABDA, were done under nitrogen using mixed anionic/nonlonic or nonionic surfactant systems with a redox Initiator, eg. t-butyl hydroperoxide plus sodium formaldehyde sulfoxylate. Base monomer addition was batch or batch plus delay comonomer additions were delay. 

Monomer and initiator must be soluble in the liquid and the solvent must have the desired chain-transfer characteristics, boiling point (above the temperature necessary to carry out the polymerization and low enough to allow for ready removal if the polymer is recovered by solvent evaporation). The presence of the solvent assists in heat removal and control (as it also does for suspension and emulsion polymerization systems). Polymer yield per reaction volume is lower than for bulk reactions. Also, solvent recovery and removal (from the polymer) is necessary. Many free radical and ionic polymerizations are carried out utilizing solution polymerization including water-soluble polymers prepared in aqueous solution (namely poly(acrylic acid), polyacrylamide, and poly(A-vinylpyrrolidinone). Polystyrene, poly(methyl methacrylate), poly(vinyl chloride), and polybutadiene are prepared from organic solution polymerizations. 

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