Acrylic latex emulsions

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. 

Latex describes the type of resin or binder used. Exterior paint usually contains 100% acrylic latex emulsions, which usually are copolymers of methylmethacrylate with butyiacrylate or 2-ethylhexylacrylate. This combination stands up well against uv radiation. Interior paint has no uv requirement, and the best combination for cost is a copolymer of vinylacetate and acrylates. Many other formulations are availabledepending on the use and quality desired. 

Typical physical properties of an acrylic latex emulsion suitable for use with cement are given in Table 5. 

Uses Emulsifier, detergent for textiles, paints, shampoos, hand creams, lotions, detergent bars flotation agent collector in ore flotation softener, lubricant for textiles, esp, cotton or rayon fibers primary surfactant and post stabilizer for acrylic and vinyl-acrylic latex emulsions Reguiatory FDA clearance... 

AH-acryHc (100%) latex emulsions are commonly recognized as the most durable paints for exterior use. Exterior grades are usuaHy copolymers of methyl methacrylate with butyl acrylate or 2-ethyIhexyl acrylate (see Acrylic ester polymers). Interior grades are based on methyl methacrylate copolymerized with butyl acrylate or ethyl acrylate. AcryHc latex emulsions are not commonly used in interior flat paints because these paints typicaHy do not require the kind of performance characteristics that acryHcs offer. However, for interior semigloss or gloss paints, aH-acryHc polymers and acryHc copolymers are used almost exclusively due to their exceUent gloss potential, adhesion characteristics, as weU as block and print resistance. 

Styrene—acrylic copolymers provide latices with good water resistance and gloss potential in both interior and exterior latex paints. However, they are typically regarded as having limited exterior durabiUty compared to all-acryhc latex emulsions that are designed for exterior use. 

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... 

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. 

In order to achieve the above objectives, three vinyl acrylic latexes of varying butyl acrylate content have been prepared and cleaned1 for use in the study. Several anionic and nonionic surfactants commonly usod in emulsion polymerization have been used to investigate the effects of surfactant structure and polymer composition on the solubilization process. Polarity of latex surface estimated from contact angle measurements have been used to study the effect of polymer polarity on surfactant adsorption. 

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. 

The author notes that his results are consistent with those of Stam-berger (27) who worked with a styrene-ethyl hexyl acrylate-acrylic acid emulsion terpolymer. At pH 8, the emulsion was stable to liquid shear, whereas at pH 3, it was unstable. There was little difference in zeta potential of the latex at the two pH values. 

The Initial phase of the development was the determination of the relative solubility of the selected pheromone, ZZ and ZE-7, 11-hexadecadlenyl acetate (Gossyplure, 1 1 ratio). In a suitable polymer matrix. Four different water-soluble or water-reducible resins were Initially Investigated a water-soluble acrylic mixture, two latex emulsions and a natural rubber colloid. Intrln- sic solubility was determined by making resln/pheromone solutions of varying concentrations and measuring the rate of pheromone diffusion from dried films. In this manner, we were able to determine the most suitable base polymer from which to begin. 

Synthetic emulsion polymers account for approximately 70% of the U.S. consumption of acrylate monomers. Major end uses for these latex polymers are coatings (32%), textiles (17%), adhesives (7%), paper (5%), and floor polishes (3%). The U.S. producers of acrylic copolymer emulsions include Rohm and Haas, Reichliold, National Starch, Union Carbide, Air Products, Unocal, B. F. Goodrich, andH. B. Fuller. 

In order to modify asphalt, 100% acrylic latex is used. Special latices are marketed for this purpose. The latex can be post-added to asphalt emulsion followed by agitation to prevent stratification. 

Acrylics. Acetone is converted via the intermediate acetone cyanohydrin to the monomer methyl methacrylate (MMA) [80-62-6]. The MMA is polymerized to poly(methyl methacrylate) (PMMA) to make the familiar clear acrylic sheet. PMMA is also used in molding and extrusion powders. Hydrolysis of acetone cyanohydrin gives methacrylic acid (MAA), a monomer which goes direcdy into acrylic latexes, carboxylated styrene—butadiene polymers, or ethylene—MAA ionomers. As part of the methacrylic structure, acetone is found in the following major end use products acrylic sheet molding resins, impact modifiers and processing aids, acrylic film, ABS and polyester resin modifiers, surface coatings, acrylic lacquers, emulsion polymers, petroleum chemicals, and various copolymers (see Methacrylic acid and derivatives Methacrylic polymers). 

Experiment Emulsion E-1614. [Rohm Haas] Acrylic latex vehicle for sealer finishes flooring materials. 

AI3-16415 EINECS 216-341-5 Geropon MLS/A Methallyl sulfonate Methallylsulfonic acid, sodium salt 2-Methyl-2-propene-1-sulfbnic acid, sodium salt NSC 2253 2-Propene-1-sulfonic acid, 2-methyl-, sodium salt Sodium 2-methyl-2-propenesulfonate Sodium 2-methylprop-2-ene-1-sulphonate. Dye improver reactive comonomer for acrylic fibers polymerization reacbve emulsifier or coemulsifier in latex emulsion polymerization. Rhdne-Poulenc. 

HASE (hydrophobically modified alkali-swellable emulsion, discussed in Chapters 25 and 28) and HEUR thickeners are readily displaced from acrylic latex surfaces (32) by sodium dodecyl sulfate (SDS). A surface-active cellulose ether was also reported (33) to desorb from monodispersed poly(styrene) latices with SDS addition. In these studies, the relative critical micelle concentrations of the anionic surfactant and thickener appear to be more important than buffering of surface charges. 

Emulsion Copolymerizations. Due to the good copolymerizability of VEC with vinyl ester monomers, it seemed likely that VEC could be incorporated into a vinyl acetate/butyl acrylate latex. First, it was important to determine if VEC is prone to hydrolysis in the acidic medium used for vinyl acetate emulsion polymerization. As a check, a single experiment was carried out using an acetic acid-sodium acetate buffer at pH=4 and heating for 4 hours at 80°C. In this experiment, 6.1% of the VEC was hydrolyzed to the 3-butene-1,2-diol. Since VEC is only soluble in water up to 3.3 %, it is expected that most of the VEC will be in the oil phase during the emulsion polymerization and that only a small amount will be hydrolyzed. 

In addition to the use of dry acrylic powders in cement mortars, other typical uses for these modifiers are in cement toppings, ceramic tile adhesives, ceramic tile grouts, white masonry paints and cement block fillers. It is obvious that these compounds are more convenient to use with the simple addition of water, than those compounds requiring the addition of a latex emulsion. As improvements are made in these dry powders, there will be more emphasis on this type of compound. At the present time, the dry powder acrylics are more costly than the latex emulsions on a dry solids basis. 

---