Ethyl acrylic acid copolymer latex

A 62 35 3 ethyl acrylate-methyl methacrylate-acrylic acid copolymer latex was prepared by continuous addition of the monomer mixture over a 4-hour period at 80° (22). The emulsifier was a sodium lauryl ether sulfate-nonylphenol polyoxyethylene adduct (20 moles ethylene oxide) mixture, the initiator a potassium persulfate-sodium hydroxulfite mixture, and the buffer a sodium bicarbonate-potassium hydroxide mixture. The final latex of pH 6.5 contained 40% solids, and the Tg of the copolymer was 13°. 

In the agglomeration step, the latexes are partially agglomerated using a core/shell agglomerating agent latex, which consists of an elastomeric 1,3-butadiene/slyrene copolymer core and an ethyl acrylate/methacrylic acid copolymer shell. This partial agglomeration operation should not be confused with a coagulation operation where the emulsion is fully destabilized (13). 

Copolymers containing allyl methacrylate have found application as an additive to other resin to enhance the properties of the system. For example, in one patent disclosure, an aqueous emulsion polymer was formed in water using 0.03 gm of sodium carbonate, 50 gm of methyl methacrylate, 2.0 gm of ethyl acrylate, and 0.1 gm of allyl methacrylate, and 0.40 gm of the sodium salt of an allyl Ci3-alkyl ester of sulfosuccinic acid. The polymerization was initiated with sodium persulfate and heated at 83°C for 1 hr. To this latex, 40 gm of butyl acrylate, 10 gm of styrene, 1.0 gm of allyl methacrylate, and another 0.40 gm of the above surfactant were added while polymerization continued. In a third... 

Yan et al. [52] explored the use of IPN techniques to produce a composite vinyl-acrylic latex. The first-formed polymer was produced using VAc and divinyl benzene (DVB), while the second formed polymer constituted a BA/DVB copolymer. In both cases the DVB was added at 0.4 wt%. They compared this product with another product, a bidirectional interpenetrating netwodc (BIPN) in which VAc was again polymerized over the first IPN. They noted that the compatibility between the phases was more pronounced in the BIPN than in the IPN as determined using dynamic mechanical measurements and C nuclear magnetic resonance spectroscopy. The concept of polymer miscibility has also been used to produce composite latex particles and thus modify the pafamance properties of VAc latexes. Bott et al. [53] describe a process whereby they bloid VAc/ethylene (VAc/E) copolymers with copolymers of acrylic acid or maleic anhydride and determine windows of miscibility. Apparently an ethyl acrylate or BA copolymer with 10-25 wt% AA is compatible with a VAc/E copolymer of 5-30 wt% ethylene. The information obtained from this woik was then used to form blends of latex polymers by polymerizing suitable mixtures of monomers into preformed VAc/E copolymers. The products are said to be useful for coating adhesives and caulks. 

The monomers which have been investigated include methyl methacrylate, ethyl acrylate ester, hydroxy acrylates and methacrylates, acrylonitrile, vinyl acetate, vinyl chloride, acrylamide, vinylidene chloride, acrylic acid, vinyl pyrollidone and styrenec Many copolymer latexes of these monomers have also been preparedc Undoubtedly the most amenable system for model studies is methyl methacrylate in aliphatic hydrocarbono... 

The only conventional synthetic thickeners used in substantial amounts in water-based coatings are the alkali-soluble emulsions (ASE). These are supplied in liquid form as low viscosity water-insoluble latexes at low pH. In use they are neutralized with anmonia or a volatile aminoalcohol to provide thickening. The most commonly used ASEs are copolymers of methacrylic acid and ethyl acrylate. Some are lightly crosslinked with a small amount (<1%) of a polyfimctional monomer to enhance viscosity. The ASEs are similar to the cellulosics in theology, but more bioresistant and somewhat more water sensitive. 

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). 

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