Methyl methacrylic acid continued

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°. 

Methyl methacrylate (melting point -48°C, boiling point 100°C, density 0.9394, flash point 9°C) is produced by the acetone cyanohydrin process in which the acetone cyanohydrin (from the reaction of acetone with hydrogen cyanide, q.v.) is reacted with sulfuric acid to yield methacrylamide sulfate, which is further hydrolyzed and esterified. The process is continuous. 

Synthesis. A series of latexes was prepared by semicontinuous emulsion polymerization of methyl methacrylate. A dialkyl ester of sodium sulfosuccinic acid surfactant yielded the narrow particle size distribution required. An ammonium persulfate/sodium metabisulfate/ferrous sulfate initiator system was used. The initiator was fed over the polymerization time, allowing better control of the polymerization rate. For the smaller size latexes (200 to 450 nm), a seed latex was prepared in situ by polymerizing 10% of the monomer in the presence of the ammonium persulfate. Particle size was adjusted by varying the level of surfactant during the heel reaction. As the exotherm of this reaction subsided, the monomer and the sodium metabisulfate/ferrous sulfate feeds were started and continued over approximately one hour. The... 

Figure 6.31 demonstrates the validity of Equation (6.134) and Equation (6.141) via noncross-linked poly(methyl methacrylate-co-methacrylic acid) (PMMA/MAA) beads. The swollen gel thickness initially increases because the rate of erosion is slow. Then a constant gel thickness follows (i.e., synchronization of swelling rate and erosion rate) and continues until the core disappears. Afterwards, the gel thickness decreases. According to Equation (6.139), the release of peptide should be linear with time, but Figure 6.31 shows a nonlinear release profile due to the decrease of surface area of spherical geometry. 

Use Manufacture of formaldehyde, acetic acid, and dimethyl terephthalate chemical synthesis (methyl amines, methyl chloride, methyl methacrylate) antifreeze solvent for nitrocellulose, ethylcellulose, polyvinyl butyral, shellac, rosin, manila resin, dyes denaturant for ethanol dehydrator for natural gas fuel for utility plants (methyl fuel) feedstock for manufacture of synthetic proteins by continuous fermentation source of hydrogen for fuel cells home-heating-oil extender. 

Esterification is finally an equilibrium reaction (35 per cent methyl methacrylate), which can be continued to completion by removing one or both of the products obtained as soon as they are formed. It takes place preferably in the liquid phase, in the presence of sulfuric acid or cation exchange resins as a catalyst, with a slight excess of methanol (1.2/1 in mol), at temperatures (110 to 115°Q apd pressures (30 to 50 kPa absolute) designed to limit polymerization reactions. The addition of an inhibitor (such as hydro-quinone) is also practised. With residence time of about 1 h. once-through conversion is total and the molar yield is close to 99 per cent. 

The copolymerization of methacrylic acid, 2-(dimethylamino)ethyl ester, and thiourea under microwave irradiation was studied by Lu et al. (Scheme 14.8) [19]. It was shown that the copolymers can be used to coordinate Cu(II) to afford coordinated copolymers which can, in turn, be used as heterogeneous catalysts in the polymerization of methyl methacrylate. The reactions were performed in a modified domestic microwave oven with a continuous power regulation. 

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... 

In situ polymerization reactions are performed in an emulsion system where an organic solution of the monomer (bearing, e.g., vinylic or acrylic moieties) is the dispersed phase and an aqueous solution containing a surfactant is the continuous phase. Methyl methacrylate has been used for the preparation of quercetin-loaded nanoparticles in a miniemulsion systum. Quercetin was shown to slower the polymerization reaction, but this effect could be attenuated by the addition of ascorbic acid. 

Gan and Chew [37,38] extended their studies to microemulsions in which all the components except water were polymerizable. Polymerization in microemulsions containing a polymerizable surfactant (sodium acrylamidoundecanoate [37] or acrylamidostearate [38]), a cosurfactant (acrylic acid), and methyl methacrylate as the continuous phase led, under certain conditions, to transparent solid terpolymers with up to 10-20% water dispersed in the polymer matrices. As in the case of copolymers, no particular structure was shown by SEM for these terpolymers. 

An equimolar amount of peroxymonosulfuric acid, prepared from 90%-H2O2 and coned. H2SO4 added below 15° to a stirred mixture of methacrolein and methanol, stirring continued at 15° for a total reaction time of 3 hrs. methyl methacrylate. Y 97% conversion 90%. F. e. s. A. Nishihara and I. Kubota, J. Org. Chem. 33, 2525 (1968). 

Methylacetylene and CO introduced continuously at 130°/13 atm. into a stirring autoclave containing Ni-carbonyl, methacrylic acid and a little water as catalysts, and hydroquinone methyl methacrylate. Y 80.5%. S. Kunichika, Y. Sakakibara, and T. Nakamura, Bull. Chem. Soc. Japan 41, 390 (1968). 

Quatemized copolymers of vinyl pyrrolidone and dimethylaminoethylthacrylate, which is cationic, have been developed for the hair care and skin care industries because of their optimal substantivity, minimum buildup, and ability to form nontacky and continuous films. Other important comonomers include vinyl alcohol, styrene, maleic anhydride, acrylamide, acrylonitrile, crotonic acid, and methyl methacrylate. 

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