Styrene methacrylic acid latexes

Styrene-N,N-Diethylaminoethyl Methacrylate-Methacrylic Acid-Latex... 

The mechanisms involved in monomer removal by post polymerisation were studied. Three redox initiator systans which generate radicals with different hydrophobidties were investigated tert-butyl hydroperoxide, hydrogen peroxide and potassium persulphate. Ascorbic acid was used as a reductant in all cases. The efficiency of these initiator systems for the removal of residual monomers from commercial latexes was studied. The examples exauuued were removal of unreacted vinyl acetate from a vinyl acetate/butyl aerylate/acrylie acid latex, methyl methacrylate from a methyl aaylate, butyl aaylate/acryhc acid latex and butyl acrylate from a butyl aaylate/styrene/ acrylic acid latex. Efficieucy of monomer ranoval by post polymerisation increased with the hydrophobidty of the radical formed from the initiator system and this was independent of the water solubihty of the residual monomer. Reasons for the observations were discussed. 35 refs. 

Journal of Applied Polymer Science 63, No.12, 21st March 1997, p.1543-55 MORPHOLOGY OF POLYISOPRENE-CO-STYRENE-CO-METHACRYLIC ACID LATEX PREPARED BY TWO-STAGE SEEDED EMULSION POLYMERISATION Karlsson O Hassander H Wesslen B Lund Institute of Technology... 

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 acryUc sheet. PMMA is also used in mol ding and extmsion powders. Hydrolysis of acetone cyanohydrin gives methacrylic acid (MAA), a monomer which goes direcdy into acryUc latexes, carboxylated styrene—butadiene polymers, or ethylene—MAA ionomers. As part of the methacrylic stmcture, acetone is found in the following major end use products acryUc sheet mol ding resins, impact modifiers and processing aids, acryUc film, ABS and polyester resin modifiers, surface coatings, acryUc lacquers, emulsion polymers, petroleum chemicals, and various copolymers (see METHACRYLIC ACID AND DERIVATIVES METHACRYLIC POLYMERS). 

Synthetic. The main types of elastomeric polymers commercially available in latex form from emulsion polymerization are butadiene—styrene, butadiene—acrylonitrile, and chloroprene (neoprene). There are also a number of specialty latices that contain polymers that are basically variations of the above polymers, eg, those to which a third monomer has been added to provide a polymer that performs a specific function. The most important of these are products that contain either a basic, eg, vinylpyridine, or an acidic monomer, eg, methacrylic acid. These latices are specifically designed for tire cord solutioning, papercoating, and carpet back-sizing. 

Polyelectrolytes provide excellent stabilisation of colloidal dispersions when attached to particle surfaces as there is both a steric and electrostatic contribution, i.e. the particles are electrosterically stabilised. In addition the origin of the electrostatic interactions is displaced away from the particle surface and the origin of the van der Waals attraction, reinforcing the stability. Kaolinite stabilised by poly(acrylic acid) is a combination that would be typical of a paper-coating clay system. Acrylic acid or methacrylic acid is often copolymerised into the latex particles used in cement sytems giving particles which swell considerably in water. Figure 3.23 illustrates a viscosity curve for a copoly(styrene-... 

The latex particle diameter produced in the emulsion copolymerization of styrene with partially neutralized poly(methacrylic acid) macromonomers, 48, was studied as a function of degree of neutralization [127]. The latex particle... 

Inaba et al. prepared a series of model styrene/butyl acrylate copolymer latexes with glass transition temperatures at room temperature. The functional monomer 2-(3-isopropenylphenyl)-2-methylethylisocyanate (TMI) was used as monomer/crosslinking agent for further film formation. A small amount of methacrylic acid was introduced in some formulations in order to enhance the crosslinking reaction. A redox initiation system was used to reduce premature crosslinking during the polymerization [82]. 

Fig. 29. Proton NMR spectrum of the copolymer latex (in CDC13) for a mole feed ratio of methacrylic acid to styrene of 0.12, internal phase ratio 0.93, AIBN 0.3 g, SDS 0.4 g and water 3 ml, polymerized first for 12 h at 40 °C. After this polymerization, additional water (twice as much as the weight of the emulsion) was added into the tubes, then polymerization continued for 2 days...

Since the methacrylic acid molecules are soluble in both styrene and water, it is important to determine the efficiency of its incorporation in the copolymer latexes. Figure 29 is an H-NMR spectrum of the copolymer latexes. The NMR peak areas of the phenyl (at 6.2-7.4 ppm) and methyl (at about 0.5 ppm) protons allow one to calculate the composition of copolymer latexes. Table 5 lists the compositions and sizes of the copolymer latexes obtained. The efficiency is quite high and increases with increasing amount of methacrylic acid. 

Styrene-butadiene rubber latex (SBR, GRS) and acrylonitrile-butadiene rubber latex (NBR) are two of the earliest to arrive on the market. Since then, many other types have appeared, with poly(vinyl acetate) and copolymers, acrylics (generally polymers and copolymers of the esters of acrylic acid and methacrylic acids), and carboxylic-SBR types being the major products. Since latices are aqueous emulsions, less... 

Recently, a series of styrene-n-butyl acrylate copolymer latexes were prepared by conventional or miniemulsion polymerization techniques which incorporated TMI and/or methacrylic acid (MAA), and the interfacial crosslinking behaviour of films derived firom these latexes was investigated [33]. It was shown that crosslinking was dramatically enhanced in the presence of MAA. However, films prepared with TMI also crosslinked in the presence of atmospheric moisture with time at room temperature. This work also demonstrated the stability of... 

Many investigators have studied polymer surfaces for years [74,75] and have been successful in determining combinations of two or more valence states [76,77] by the mathematical process of deconvoluting the peak assignments [78]. It was only recently that latexes were examined by ESCA. Davies et al. [79] prepared a series of homopolymers of poly(methyl methacrylate) (PMMA) and poly(butyl methacrylate) (PBMA), and also poly[(methyl methacrylate)-co-(butyl methacrylate)] (PMMA-PBMA), by surfactant-free emulsion polymerization. It was found that the surface of the latex film was rich in PMMA, which may possibly be explained by the reactivity ratios for the MMA/BMA system (ri = 0.52 and rj = 2.11) [80], Recently, Arora et al. carried out angle-dependent ESCA studies on a series of films prepared from core-shell ionomeric latexes (with a polystyrene core and a styrene/n-butyl acrylate/ methacrylic acid copolymer shell) to determine the distribution of carboxyl groups in the films [81,82]. 

This chapter concludes with brief reference to carboxylated rubber latexes. Further information, with references, is available in a review by Blackley [27]. Carboxylated rubber latexes contain rubbery polymers which have been modified by inclusion of a small amount of a copolymerisable carboxylic-acid monomer in the emulsion polymerization system by which they were prepared. Typical carboxylic-acid monomers are acrylic acid (XI), methacrylic acid (XII) and itaconic acid (XIII). The most industrially-important rubber latexes of this type are the carboxylated styrene-butadiene rubber latexes. Also of considerable... 

Muller and coworkers prepared disc-like polymer Janus particles from assembled films of the triblock copolymer SBM and, after hydrolysis of the ester groups into methacrylic acid units, used these as Pickering stabilizer in the soap-free emulsion polymerization of styrene and butyl acrylate [111]. Armes and coworkers described the synthesis of PMMA/siUca nanocomposite particles in aqueous alcoholic media using silica nanoparticles as stabilizer [112], extending this method to operate in water with a glycerol-modified silica sol [113, 114]. Sacanna showed that methacryloxypropyltrimethoxysilane [115] in the presence of nanosized silica led to spontaneous emulsification in water, which upon a two-step polymerization procedure afforded armored particles with an outer shell of PMMA [116]. Bon and coworkers demonstrated the preparation of armored hybrid polymer latex particles via emulsion polymerization of methyl methacrylate and ethyl methacrylate stabilized by unmodified silica nanoparticles (Ludox TM O) [117]. Performance of an additional conventional seeded emulsion polymerization step provided a straightforward route to more complex multilayered nanocomposite polymer colloids (see Fig. 14). 

Chem. Descrip. 50% Methacrylamidoethylethyleneurea, 20% methacrylic acid, 30% water, 2000 ppm hydroquinone inhibitor Uses Monomer for emulsion polymerization of acrylic, vinyl-acrylic, and styrene-acrylic latex paints with improved wet adhesion, wet scrub resist., solv. resist. adhesion promoter in water- and solv.-based coatings and adhesives... 

Chem. Descrip. Dioctyl maleate CAS 2915-53-9 EINECS/ELINCS 220-835-6 Uses Comonomer used in polymerization with vinyl acetate, vinyl chloride, styrene and derivs. of acrylic and methacrylic acids used in latex paints, textiles as specialty plasticizer Properties APHA50 max. liq. m.w. 340 sp.gr. 0.939-0.944 vise. 9.1-9.5 cs (100 F) pour pt. -75 F acid no. 0.10 max. flash pt. (COC) 370 F ref. index 1.452-1.454 94% act. 

Polymers for Advanced Technologies 9, No. 12, Dec.1998, p.844-50 STUDY OF POLY(STYRENE/BUTYL ACRYLATE/METHACRYLIC ACID) COPOLYMER LATEXES WITH TRIMODAL PARTICLE SIZE DISTRIBUTION Fuxiang Chu Guillot J Guyot A CNRS-LCPP... 

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