Topic
Methacrylic acid
About: Methacrylic acid is a research topic. Over the lifetime, 13058 publications have been published within this topic receiving 173201 citations. The topic is also known as: α-Methacrylic acid & 2-Methylacrylic acid.
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TL;DR: In this paper, an effective fabrication procedure of polymethylmetacrylate-co-metacrylic acid coatings with controlled number of surface carboxyl groups was developed.
42 citations
TL;DR: When wool fibres are impregnated with a dilute solution of ferrous ammonium sulphate, dried, and then treated with a solution of methacrylic acid containing a trace of hydrogen peroxide, preferential internal polymerisation is brought about by the hydroxyl radicals formed inside the fibres when the hydrogen-peroxide encounters the ferrous ions as mentioned in this paper.
Abstract: When wool fibres are impregnated with a dilute solution of ferrous ammonium sulphate, dried, and then treated with a solution of methacrylic acid containing a trace of hydrogen peroxide, preferential internal polymerisation is brought about by the hydroxyl radicals formed inside the fibres when the hydrogen peroxide encounters the ferrous ions. The reaction proceeds best at low j>H values in absence of oxygen. Preferential internal polymerisation of water–insoluble monomers can also be brought about if they are emulsified with Lissolamine V, and no difficulty has been encountered in forming copolymers of methacrylic acid and methyl methaerylate, for example, within the fibres.
Such internal deposits of polymer can be used to modify the properties of wool in a number of ways. When the polymer is acid, two–tone effects can be obtained by dyeing treated and untreated wool in the same dyebath, the treated wool taking a lighter shade. Conversely, when the polymer is basic, the treated wool takes a darker shade. In addition, internal deposits of polymer are capable of increasing the wear–resistance and reducing the milling shrinkage of wool fabrics. Finally, if the monomer carries reactive side–chains, e. g. methacrylamide, internal polymerisation followed by cross–linking with formaldehyde causes a striking increase in the resistance of wool fibres to extension in water. It is not yet known whethor cross–linkages are formed between the polymer and the wool, but reactions of this type should be useful in strengthening intact fibre and repairing damaged fibres.
42 citations
Patent•
30 Jul 1965
TL;DR: In this article, the dispersion stabilizer is formed by copolymerizing in solution in an organic solvent an ethylenically unsaturated monomer, which provides the backbone, and a chain-like macromonomer (molecular weight at least 500) having only one terminal unsaturated group per molecule.
Abstract: Dispersions of polymer particles in an organic liquid in which the polymer is insoluble are prepared by polymerizing an ethylenically unsaturated monomer in the liquid which contains a dispersion stabilizer, the latter being a polymeric substance comprising a polymeric backbone which is non-solvated by the liquid and attached thereto, on average, at least 5 side chains which are solvated by the liquid, the molecular weight of the side chains being at least 500 and the weight ratio of the attached side chains to the backbone being from 0.5: 1 to 5: 1 respectively. In the dispersion stabilizer, the side chains may be attached to the backbone by a condensation reaction involving, for example, the formation of ester, ether, amide or urethane links; preferably, however, the stabilizer is formed by copolymerizing in solution in an organic solvent an ethylenically unsaturated monomer, which provides the backbone, and a chain-like macromonomer (molecular weight at least 500) having only one terminal ethylenically unsaturated group per molecule, which provides the side chains, the macromonomer being of different polarity to the resulting backbone. In examples the stabilizers are prepared by (1) copolymerizing the reaction product of 12-hydroxystearic acid dimer and glycidyl methacrylate with methyl methacrylate in a hydrocarbon solvent using benzoyl peroxide catalyst together with primary octyl mercaptan, (2) copolymerizing the reaction product of poly-12-hydroxystearic acid and glycidyl methacrylate with methyl methacrylate and methacrylic acid in ethyl/butyl acetate using azodiisobutyronitrile catalyst, (3) solution polymerizing the methacrylate ester of a commercial mixture of C8-C10 aliphatic alcohols using 4,41-azobis-(cyanovaleric acid) catalyst together with thioglycollic acid, esterifying the terminal carboxyl groups of the product with glycidyl methacrylate, and copolymerizing the ester product with methyl methacrylate and methacrylic acid in ethyl acetate using azobis(isobutyronitrile) catalyst, (4) interesterifying the terminal carboxyl group of poly-12-hydroxystearic acid with vinyl acetate (to introduce a terminal vinyl group into the polymer chain) and copolymeriizing the product with vinyl acetate and acrylic acid in ethyl/butyl acetate using azodiisobutyronitrile catalyst, (5) solution polymerizing methyl methacrylate using 4,41-azobis(cyanovaleric acid) together with thioglycollic acid, terminally esterifying as in (3), and copolymerizing the ester product with vinyl pyrrolidone, (6) copolymerizing the terminal ester product obtained in (5) with dimethylaminoethyl methacrylate using azodiisobutyronitrile catalyst. Use of some of these particular stabilizers is illustrated wherein methyl methacrylate and methacrylic acid are copolymerized in a solvent in the presence of azodiisobutyronitrile with or without primary octyl mercaptan. The stabilizer of process (4) is suitable for polymeriizing vinyl acetate in aliphatic hydrocarbon.ALSO:In Example 1, 12-hydroxystearic acid dimer is esterified with glycidyl methacrylate by refluxing in solution in an aliphatic hydrocarbon (b.p. 100-120 DEG C.) in the presence of hydroquinone (polymerization inhibitor) and a tertiary base catalyst.
42 citations
TL;DR: In this paper, the role of excess acid groups in the chain and ion dynamics of E/MAA ionomers was investigated using a combination of melt rheometry and cation diffusion experiments, and it was shown that the excess acid group act not by introducing a separate relaxation mechanism, but by accelerating the rate of ion hopping in these materials, which in turn speeds up chain relaxation proportionately.
Abstract: Ethylene−methacrylic acid (E/MAA) ionomers are commonly neutralized to substoichiometric levels, leaving unneutralized (“excess”) carboxylic acid groups along the chain. Previous observations indicate that these excess acid groups interact preferentially with the ionic units and produce a reduction in viscosity. Here, we employ a combination of melt rheometry and cation diffusion experiments to elucidate the role of these excess acid groups in the chain and ion dynamics of E/MAA ionomers. We find that the excess acid groups act not by introducing a separate relaxation mechanism, but by accelerating the rate of ion hopping in these materialsa “plasticization” of the ionic interactionswhich in turn speeds up chain relaxation proportionately. At low ion contents, the functional dependence of viscosity vs ion content is profoundly altered by excess acid groups, due to the competing effects of viscosity increase through interacid hydrogen bonding and viscosity reduction through plasticization of the ionic asso...
42 citations
TL;DR: In this article, the fluorescence and fluorescence decay profiles of pyrene and 1-ethylpyrene in solutions of a hydrophobic alkali-swellable emulsion (HASE) polymer were examined to characterize the association structure formed from the hydrophilic substituents.
Abstract: The fluorescence and fluorescence decay profiles of pyrene and 1-ethylpyrene in solutions of a hydrophobic alkali-swellable emulsion (HASE) polymer were examined to characterize the association structure formed from the hydrophobic substituents. The HASE polymer was obtained by the copolymerization of ethyl acrylate (EA), methacrylic acid, and a macromonomer containing a C20H41 group separated from the backbone by 32 ethylene oxide units. We examine solutions neutralized with 1 equiv of NaOH, at polymer concentrations where virtually all of the added probe is partitioned into hydrophobic domains of the polymer. Both monomer and excimer emission are observed, and IE/IM increases in proportion to the amount of probe added to the system. Individual monomer fluorescence decay profiles fit well to the traditional micelle Poisson quenching model, but attempts to calculate the hydrophobe aggregation number NR led to values that changed markedly with the ratio of probe to polymer. These results were rationalized ...
42 citations