Showing papers on "Methacrylic acid published in 1979"

Equilibrium study of polymer–polymer complexation of poly(methacrylic acid) and poly(acrylic acid) with complementary polymers through cooperative hydrogen bonding

Abstract: The degree of linkage, θ, defined as the ratio of the binding groups to the total of potentially interacting groups and the stability constant K of the polymer–polymer complexes in the systems poly(methacrylic acid)–poly(ethylene glycol), poly(acrylic acid)–poly(ethylene glycol), and poly-(methacrylic acid)–poly(vinyl pyrrolidone) in aqueous and aqueous alcohol media were determined as a function of temperature by potentiometric titration. It was found that θ and K are strongly dependent on chain length, temperature, and medium and that hydrophobic interaction is a significant factor in the stabilization of the complexes. The enthalpy and entropy changes and the cooperativeness parameter of the systems were calculated. A mechanism for the complexation in terms of cooperative interaction was proposed.

Polysiloxane/acrylic acid/polcyclic esters of methacrylic acid polymer contact lens

Abstract: Monomeric polysiloxanes end-capped with activated unsaturated groups polymerized with acrylic acid and a comonomer comprising a polycyclic ester of acrylic acid or methacrylic acid to form a hydrophilic, water absorbing contact lens is disclosed. These polysiloxane polymer contact lenses are unexpectedly capable upon hydration of retaining from 1 percent to about 99 percent by weight of water, based upon the total weight of the dry, i.e., unhydrated polymer.

Cationic hydrogels based on hydroxyalkyl acrylates and methacrylates

Abstract: Novel cationic hydrogels, containing basic (cationic) groups in their molecular structure, and processes for their preparation are described. These novel hydrogels are three-dimensional polymer networks, having good water permeability and mechanical properties, and are obtained by simultaneous polymerization and crosslinking, in the presence of a polymerization catalyst, such as an organic peroxide, azobisisobutyronitrile or other free radical polymerization catalyst, of a mixture of (a) hydroxyalkyl acrylate or methacrylate, (b) a cationic monomer - usually an ester of acrylic or methacrylic acid with an amino alcohol, the terminal amino group of which may be quaternized, such as dimethylaminoethyl methacrylate or acrylate and the quaternized derivatives thereof, and (c) a cross-linking agent, such as glycol diacrylate or dimethacrylate; if desired there may also be present (d) one or more additional monomers, usually an acrylic monomer such as an alkyl acrylate or methacrylate, acrylamides etc. (although other monomers such as vinyl acetate, styrene, etc. may also be used) which is copolymerizable with (a), (b) and (c). The thus obtained cationic hydrogels are useful for combining, by reaction or complexing, with materials having an opposite charge; such as acidic or anionic agricultural chemicals (insecticides, herbicides, fungicides, plant growth regulators, etc.), germicides, pharmaceuticals, cosmetics, hormones, enzymes, flavors, fragrances, antiperspirants, metals and the like, both to recover such acidic or anionic materials from an aqueous medium and for purifying water containing them, and also for the preparation of a complex or other combination of the cationic hydrogel with such materials which may be useful per se or from which the complexed or combined acidic or anionic material may be slowly or controllably released.

Liquid emulsion polymers, process for preparing them and aqueous compositions thickened with these emulsions

Abstract: Novel aqueous liquid emulsion polymers are prepared by the copolymerization of (A) 15-60 weight percent of a C 3 -C 8 α,β-ethylenically unsaturated carboxylic acid monomer, preferably acrylic or methacrylic acid or a mixture thereof with itaconic or fumaric acid, (B) 15-80 weight percent of a nonionic copolymerizable C 2 -C 1 2 α,β-ethylenically unsaturated monomer, preferably a monovinyl ester such as ethyl acrylate or a mixture thereof with styrene, acrylonitrile, vinyl chloride or vinyl acetate, and (C) 1-30 weight percent of certain nonionic vinyl surfactant esters, such as nonyl- phenoxypoly (ethyleneoxy) 9 ethyl acrylate, to give an emulsion copolymer stable as an aqueous colloidal dispersion at an acid pH lower than about 5.0 but responsive to pH adjustment with base. These emulsion polymers adjusted to a pH of 5.5-10.5 or higher are effective thickeners for a wide variety of aqueous systems including cosmetic products, drilling muds, and particularly aqueous coating compositions such as latex paint.

PMMA copolymers as high sensitivity electron resists

Abstract: Copolymers of methyl methacrylate and methacrylic acid have been shown to have higher sensitivity and thermal stability than PMMA as electron resists. A new method is presented which allows further sensitivity improvement through the use of multiple resist layers consisting of PMMA and copolymers of PMMA or entirely copolymers with different methacrylic acid content. Such combinations allow electron resist sensitivity as high as 2×10−6C/cm2 with temperature stability of over 160°C.

Effect of carboxylic monomers on acid distribution in carboxylated polystyrene latices

Abstract: A study was made of the effect of carboxylic monomers, such as itaconic acid, acrylic acid, and methacrylic acid, on the relative distribution of acid in the aqueous serum phase to that on the latex surface to that buried in the particle of carboxylated polystyrene latices prepared by emulsion polymerization. The relative acid distribution of the carboxylated latices was determined by the conductometric titration method of Hen. Effect of carboxylic monomer levels and latex particle size on acid distribution ratio are given. It is shown that itaconic acid, being the most hydrophilic and having the least solubility in styrene, tends to distribute itself in favor of the aqueous serum phase, while acrylic acid, which has limited solubility in styrene and being sufficiently hydrophilic, tends to prefer the particle surface predominantly. Methacrylic acid, being the most hydrophobic of the three carboxylic monomers studied and having good solubility in styrene, is shown to be concentrated inside the particle core. The observed results are compared with other similar findings in the literature and analyzed in the light of accepted mechanisms for emulsion polymerization of carboxylated styrene systems.

Powder coating composition composed of ethylene resin mixture and hydrocarbon wax

Abstract: A powder coating composition comprising (A) 70 to 97% by weight of an ethylene resin mixture composed of (A-1) an ethylene copolymer having a melt index of 1 to 50 and containing at least one comonomer selected from the group consisting of alpha-olefins other than ethylene, dienes, vinyl acetate, vinyl alcohol, acrylic acid, functional derivatives of acrylic acid, methacrylic acid and functional derivatives of methacrylic acid, and (A-2) a graft copolymer of polyethylene having grafted thereto an unsaturated carboxylic component, the amount of said unsaturated carboxylic component being 0.001 to 2% based on the weight of the ethylene resin mixture (A), and (B) 3 to 30% by weight of a hydrocarbon wax having a number average molecular weight of about 400 to about 3,000 and a density of not less than 0.9 g/cm 3 , said wax having an acid value of up to about 5 when it is a modified wax.

Graft polymerization of vinyl acetate onto starch. Saponification to starch–g–poly(vinyl alcohol)

Abstract: at a radiation dose of 1.0 IvIrad. However, over half of the polymer was present as ungrafted poly­ (vinyl acetate) (grafting efficiency less than 50%), and the graft copolymer contained only :34'1,) grafted synthetic polymer (:34% add-on). Lower irradiation doses produced lower conversions of monomer to polymer and gave graft copolymers with lower % add-on. Addition of minor amounts of acryl­ amide, methyl acrylate, and methacrylic acid as comonomers produced only small increases in % add-on and grafting efficiency. However, grafting efficiency was increased to 70% when a monomer mixture containing about 10% methyl methacrylate was used. Grafting efficiency could be increased to over 90% if the graft polymerization of vinyl acetate-methyl methacrylate was carried out near O°C, although conversion of monomers to polymer was low and grafted polymer contained 40-50',\0 poly(methyl methacrylate). Selected graft copolymers were treated with methanolic sodium hy­ droxide to convert starch-g-poly(vinyl acetate) to starch-g-poly(vinyl alcohol). The molecular weight of the poly(vinyl alcohol) moiety \vas about 30,000. The solubility of starch-g-poly(vinyl alcohol) in hot water was less than .50%; however, solubility could be increased by substituting either acid-modified or hypochlorite-oxidized starch for unmodified starch in the graft polymerization reaction. Vinyl acetate was also graft polymerized onto acid-modified starch which had been dis­ persed and partially solubilized by heating in water. A total irradiation dose of either 1.0 or 0.5 Mrad gave starch-g-poly(vinyl acetate) with about :35% add-on, and a grafting efficiency of about 40');, was obtained. A film cast from a starch-g-poly(vinyl alcohol) copolymer in which homopolymer was not removed exhibited a higher ultimate tensile strength than a comparable physical mixture of starch and poly(vinyl alcohol).

Process for producing methacrylic acid and a catalyst

Abstract: The present invention relates to a process for producing methacrylic acid by oxidizing methacrolein in vapor phase with molecular oxygen or a gas containing molecular oxygen, characterized in that the oxidation is carried out in the presence of a catalyst having a composition shown by the following formula: Moa Vb Pc Xd Ye Of wherein Mo, V, P and O respectively represent molybdenum, vanadium, phosphorus and oxygen; X represents at least one element selected from the group consisting of potassium, rubidium, cesium, and thallium; Y represents at least one element selected from the group consisting of copper, silver, tin, thorium, germanium, nickel, iron, cobalt, titanium, rhenium, chromium, cerium, antimony and magnesium; and a, b, c, d, e and f denote the atomic ratio of respective elements where, a is 10, b is a number of 6 or less than 6 excluding 0, preferably 0.5 to 3, c is a number of 0.5 to 6, preferably 0.5 to 3, d is a number of 0.5 or less than 0.5 excluding 0, preferably 0.01 to 0.3, e is a number of 5 or less than 5 exclusing 0, preferably 0.01 to 1 and f is a number determined by the valence and atomic ratio of the other elements and usually is a number of 35 to 80, and comprising heteropolyacid having the elements above-mentioned as its components and X-metal salt of the heteropolyacid both of which are present in a mixed state, and relates also to the above-mentioned catalyst.

Deformational, swelling, and potentiometric behavior of ionized gels of 2‐hydroxyethyl methacrylate–methacrylic acid copolymers

Abstract: The deformational, swelling, and potentiometric behavior of ionized water-swollen gels of 2-hydroxyethyl methacrylate (HEMA)–methacrylic acid (MA) copolymers used in biomedical and separation applications was investigated. With increasing degrees of neutralization α, the swelling degree strongly increases and the modulus Gs decreases. For the copolymers with MA content ⩾ 30 mole-%, the dependence of Gs on α passes through a minimum. Comparison of the results with the modified theory of rubber elasticity shows that the decrease in Gs at low concentrations of charges on the chain is controlled mainly by the degree of swelling. At higher α, both the finite extensibility of network chains, caused by a high degree of swelling, and electrostatic interactions contribute to Gs. The dependence of the interaction parameter χ on the volume fraction of polymer in the gel, v2, is independent of α and closely resembles the dependence obtained for other hydrophilic polymers.

Speed enhancement of PMMA resist

Abstract: The enhancement of the electron beam sensitivity of PMMA from 10−5 C/Cm2 to the 10−6 C/cm2 range has been achieved by incorporation of 15 mol % methacrylic anhydride (MAN) groups into the polymer chain. The MAN group is introduced by cyclization of a copolymer of PMMA–MA (poly methyl methacrylate–methacrylic acid) into a terpolymer of PMMA–MA–MAN of 70/15/15 mol % composition. The terpolymer retains all of the exemplary properties of PMMA; high resolution, excellent adhesion, ease of processing and process versatility. The resist has been used for lift‐off metallurgy deposition, chrome mask fabrication, and for wet and dry etching of insulators. The enhancement of the sensitivity is primarily due to the higher chain scission and gaseous product formation. The incorporation of the anhyride group also increases the thermal stability of PMMA from 135° to 175°C.

Methylmethacrylate metabolism in man. The hydrolysis of methylmethacrylate to methacrylic acid during total hip replacement.

Abstract: Methylmethacrylate, the monomeric component of the polymethylmethacrylate cement used in orthopedic surgery, has been shown to undergo hydrolysis to methacrylic acid during hip replacement operations. Circulating levels of methacrylic acid were comparable with those of methylmethacrylate. Concentrations of both methylmethacrylate and methacrylic acid normally lay in the range 0--15 micrograms/cc. No correlation could be discerned between changes in the concentrations of methylmethacrylate and methacrylic acid, and changes in blood pressure.

A process for producing methacrolein and methacrylic acid

Abstract: OF THE DISCLOSURE: A process for producing methacrolein and methacrylic acid by vapor phase oxidation of isobutylene and/or tertiary butanol with molecular oxygen or a molecular oxygen-containing gas in the presence of the catalyst represented by the following formula: MoaVbPcXdOe (wherein X represents at least one element selected from the group consisting of Cu, Ag, Zn, Cd, Al, Ge, Sn, Pb, Sb, Bi, Mg, Ca, Sr, Ba, Ti, Zr, Nb, Ta, W, Mn, Fe, Co, Ni, Ce, Th, Re, Cr, B, K, Rb and Cs, and a, b, c, d and e represent the atomic ratio of the elements where, a is 10, b is a number of 6 or less than 5 excluding 0, preferably 0.5 to 3, c is a number of 0.5 to 10, preferably 0.5 to 3, d is a number of 0.01 to 5, preferably 0.01 to 2.0, and e is a number determined depending on the valency and atomic ratio of the other elements present and is usually a number of 35 to 80).

Process for preparing heteropoly-acids

Abstract: An aq slurry of Mc, V, and P oxides or oxyacids, in the approx ratio desired in product, was heated at 60-250OC and l atm-30kg/cm2 ; a heteropolyacid was crystd out The heteropolyacids are useful as dehydrogenation catalysts, eg, in prepg methacrylic acid from isobutyric acid Thus, powd MoO3 360, V2O5 638 and H3PO4 288g in 2l H2O were refluxed with air injection for 20 days, filtered, concd to 300ml, to obtain red crystals of H5M10V2PO40

Catalyst and process for producing methacrylic acid

Abstract: A catalyst composition useful for the oxidation of unsaturated aldehydes, particularly the oxidation of methacrolein to produce methacrylic acid, comprises the combination of oxides of molybdenum, copper, phosphorus, antimony, and cesium and/or calcium and optionally may include one or more of the elements Ni, Zn, Ru, Rh, Pd, Pt, As, K, Rb, Sr, Ba, Cr, V, Nb, W, Mn, Re, and rare earth metals including La.

Fluorination of polyhydrofluoroethylenes. II. Formation of perfluoroalkyl carboxylic acids on the surface region of poly(vinylidene fluoride) film by oxyfluorination, fluorination, and hydrolysis

Abstract: Oxyfluorination and postfluorination behaviors of poly(vinylidene fluoride) films, as well as hydrolysis of the films treated so far, have been studied by infrared (IR) spectrometry. By exposing the polymer film to a mixture of oxygen and fluorine at about 90°C acyl fluoride groups attendant on the scission of the polymer chains were formed. The oxyfluorinated molecules could be further perfluorinated with fluorine alone at about 90°C, leaving many of the acyl fluoride groups. When the properly oxyfluorinated and postfluorinated film was further treated with a hot 6M sodium hydroxide solution the opaque layer of perfluoroalkyl sodium carboxylate of high molecular weight was formed on the surface of the film, to about 3 μm in thickness, which behaved as a cation exchanger. This new type of cation exchanger of perfluoroalkyl carboxylic acid was significantly more acidic than the usual methacrylic acid exchanger. It was able to adsorb the sodium ions from a neutral sodium chloride solution up to about 70% of the exchange capacity and to keep the ions stable while washing them with water, though it could be regenerated to the hydrogen form with a dilute acetic acid solution. The nature of the new ion exchanger has been examined in some detail by IR spectrometry with Li+, Na+, and Cs+ ions.

Preparation of aqueous polyacrylate dispersions having improved flow characteristics

Abstract: Aqueous polyacrylate dispersions having improved flow characteristics are prepared by polymerizing esters of acrylic acid and/or methacrylic acid and alkanols of 1 to 10 carbon atoms, with or without admixture of styrene and/or vinyl esters and/or water-soluble monoolefinically unsaturated comonomers (the monomer feed being in the form of an emulsion), in aqueous emulsion in the presence of a free radical polymerization initiator, a protective colloid, a nonionic emulsifier and a regulator, at least a part of the protective colloid being introduced into an aqueous initial charge, and a water-soluble regulator being employed in the initial charge and in the feed.

Study of Metal-Polycarboxylate Complexes Employing Ion-selective Electrodes. II. Stability Constants of Copper(II) Complexes with Poly(acrylic acid) and Poly(methacrylic acid)

Abstract: The copper(II) complex formation with poly(acrylic acid) and poly(methacrylic acid) in aqueous solution was studied by potentiometric titration employing glass and copper(II) ion-selective electrodes. The values of the equilibrium constants of the complex formation and the stability constants were estimated in various degree of neutralization. Since the concentration of free copper(II) ions could be determined by employing the copper(II) ion-selective electrode, the concentrations of two complex species, involving one and two carboxylato groups, were determined from stoichiometric equations. The equilibrium and stability constants of the complexes obtained were observed to pass through peaks with increase in the degree of neutralization. The order of magnitude of the equilibrium constant of the polyacrylate complex was larger than that of the polymethacrylate complex.

Unsaturated poly-(carbonate-urethanes) and their applications to photocrosslinking

Abstract: The invention relates, by way of new products, to poly-(carbonate-urethanes) with acrylic or methacrylic acid terminal groups, of the formula ##STR1## in which X represents either hydrogen or the methyl group, R represents a substituted or unsubstituted alkylene, cycloalkylene or arylene radical, R' represents a lower alkylene radical, Z represents a polycarbonate chain and C, H, N and O respectively represent carbon, hydrogen, nitrogen and oxygen. The unsaturated poly-(carbonate-urethanes) according to the invention are obtained by condensing a diisocyanate with a polycarbonate-diol and a lower hydroxyalkyl acrylate or methacrylate. They constitute a base for photocrosslinkable compositions which resist hydrolysis and possess a good adhesion.

Method for making N-substituted acrylamides and methacrylamides

Abstract: What is disclosed is the method for making an N-substituted acrylamide or an N-substituted methacrylamide which comprises reacting an alkyl ester of acrylic acid or of methacrylic acid with an aliphatic amine or with an aromatic amine at a temperature between 50° C. and 180° C. in the presence of a catalytic amount of a dialkyl tin oxide.

Catalytic oxide composition for preparing methacrylic acid

Abstract: A process for preparing methacrylic acid which comprises carrying out the catalytic vapor phase oxidation of methacrolein with a member selected from the group consisting of air and a molecular oxygen-containing gas in the presence of a novel catalytic oxide composition of the general formula Y.sub.a X.sub.b P.sub.c Mo.sub.d V.sub.e O.sub.f wherein Y is at least one metallic element selected from the group consisting of copper, cobalt, zirconium, bismuth, antimony and arsenic. X is at least one alkali metal element selected from the group consisting of sodium, potassium, rubidium and cesium, and a, b, c, d, e and f represent the atomic ratios of the several elements; and when d is 12, a is 0-10 and b is 0-10, c is 0.1-10, e is 0.1-10, and f is a value that is determined by the valences and atomic ratios of the several elements, with the proviso that the sum of a plus b is greater than zero.

Photoviscosity Effect of Polymer Solutions

Abstract: Poly(methyl methacrylate) and poly(methacrylic acid) having spirobenzopyran in the side groups and polyamide having azobenzene in the main chain were synthesized in attempting to construct photoresponsive polymer systems, the conformation of which can be photoregulated. The solution viscosity in benzene of poly(methyl methacrylate) containing spirobenzopyran groups (9 mole% in base unit) during irradiation was found to be 12% lower than the viscosity in the dark. The viscosity is restored to the initial value in less than 3 min in the dark after cutting off the light. A study of the solvent effect and a spectroscopic study have verified that the photoviscosity effect is due to the self-solvation of the ester side groups to the photo-produced merocyanines. Photoregulation of the polymer conformation was also achieved in methanol for poly(methacrylic acid) having spirobenzopyran and in dimethylacetamide for a polyamide having azobenzene in the main chain.

Photopolymerisable mixture and light-sensitive coating material

Abstract: 1. A photopolymerizable mixture, comprising a polymeric binder which is soluble or at least swellable in aqueous-alkaline solutions, a compound with at least two acrylic or methacrylic acid ester groups and a boiling point above 100 degrees C which is capable of addition polymerization, a photo-initiator, and a plasticizer, characterized in that the plasticizer is a compound corresponding to Formula I see diagramm : EP0006125,P11,F2 wherein R1 is a hydrogen or halogen atom or an alkyl group with 1 to 4 carbon atoms, R2 is a hydrogen atom, an OH group, or an alkyl group with 1 to 4 carbon atoms, R3 is a hydrogen atom or a methyl group, R4 is an alkyl or alkenyl group with 1 to 20 carbon atoms, and n is zero or a whole number from 1 to 20, and wherein R1 has at least 4 carbon atoms if n is zero or 1.

Metastable ion studies. XII—Molecular and fragment ion structures for isomeric C4H6O2 acids

Abstract: Metastable peak characteristics, ionization and appearance energy data and isotopic labelling experiments have been applied to a study of the fragmentation behaviour of the molecular ions of the isomeric C4H6O2C acids, cis and trans-crotonic acids, methacrylic acid, butenoic acid and cyclopropane carboxylic acid. Prior to the losses of H2O and CH3, all the metastable molecular ions rearrange to [cis-crotonic acid]+⋅ ions. Loss of H2O, which generates a composite metastable peak, is proposed to yield vinylketene and/or cyclobutenone molecular ions. Detailed mechanisms are presented for the isomerizations of the various molecular ions and for the above fragmentations. Ionized 3-butenoic and cyclopropane carboxylic acids display a major loss of CO from their metastable ions, a minor process in the other isomers. The metastable peaks consist of two components and these are ascribed to the formation of propen-1-ol and allyl alcohol as daughter ions. Some comparative data are presented for the isomeric C5H8O2 acids, tiglic acid, angelic acid and senecioic acid.

Dispersions of hydrophilic acrylic resins

Abstract: Aqueous dispersions of copolymers of (1) acrylic or methacrylic acid esters, (2) derivatives of acrylic acid or methacrylic acid having the general formula ##STR1## wherein Y is oxygen or a --NR"-- group where R" is hydrogen or alkyl having 1-4 carbon atoms, R is hydrogen or methyl, R' is hydrogen or alkyl having 1-4 carbon atoms, and n is an integer from 1 to 25, (3) one or more polymerizable carboxylic acids and/or the salts thereof, and (4) one or more monomers capable of crosslinking the polymer chains. These copolymers are highly water absorbent, and alkali-resistant, and applied as dispersions are well suited for providing a hydrophilic finish to textile fibers and to textiles and non-wovens.

Stereochemistry of the conversion of methacrylate to β-hydroxyisobutyrate in Pseudomonas putida

Abstract: Stereospecifically labelled (2S,3S+ 2R,3R)-[2,3-2H2]-β-hydroxyisobutyric acid methyl ester benzoate was synthesized and used to assign the Eu(fod)3 shifted n.m.r. signals of the C-3 hydrogens of the unlabelled analogue. (E)-[3-2H1]Methacrylic acid was converted by Pseudomonas putida(ATCC 21244) to (2S,3S)-[3-2H1]-β-hydroxyisobutyric acid. The results show that the hydration of methacrylate to S-(+)-β-hydroxyisobutyric acid in this organism, probably via methacrylyl-CoA, proceeds stereospecifically by syn hydration.

Process of preparation of emulsifier-free rubber latices

Abstract: 1. Process for the production of an emulsifierfree rubber latex from 1 to 6 parts by weight of methacrylic acid and 94 to 99 parts by weight of a mixture of 10 to 90 parts by weight of one or more acyclic conjugated dienes containing 4 to 9 carbon atoms and 10 to 90 parts by weight of one or more arylvinyl monomers containing 8 to 12 carbon atoms and/or (meth)acrylonitrile, the quantity of (meth)acrylonitrile being at most 50 parts by weight, characterized, in that a) an aqueous emulsion is prepared by adding at least one part of methacrylic acid, one part of diene and other monomers to water, b) polymerisation is initiated by adding an aqueous basic solution of a peroxodisulphate, which contains such a quantity of organic or inorganic bases that the polymerisation takes place at a pH of between 3.5 and 7, c) polymerisation is carried out in a first stage at a pH value of between 3.5 and 7 and a temperature above 70 degrees C until at least 50 % of the monomers have been converted, d) the remainder of the monomers and more aqueous basic peroxodisulphate solution, which contains such a quantity of organic or inorganic bases that the polymerisation takes place at a pH of between 3.5 and 7, are added in one or more further stages, e) the polymerisation is continued at a pH value of 3.5 to 7 and at above 70 degrees C until at least 50 % of the monomers have, in each case, been converted and, in the final stage, until 85 to 100 % of the monomers have been converted.