Showing papers on "Methacrylic acid published in 1990"

Absorbent Polymer Technology

Abstract: Section I. Fundamentals of Absorbent Materials: Preparation, Structure, and Characterization. 1. The evolution of absorbent materials (J.R. Gross). 2. Preparation and structure of polyacrylates (F.L. Buchholz). 3. Preparation and characterization of crosslinked hydrophilic networks (L. Brannon-Peppas). 4. The equilibrium swelling behavior of porous and non-porous hydrogels (L. Brannon-Peppas and N.A. Peppas). 5. Characterization of ionic water-absorbent polymers: Determination of ionic content and effective crosslink density (D.C. Harsh and S.H. Gehrke). 6. Swelling behavior of water-soluble cellulose derivatives (E. Doelker). 7. Structure and swelling behavior of poly(ethylene glycol)/poly(methacrylic acid) complexes (J. Klier and N.A. Peppas). 8. Transport in porous polymers (W.M. Saltzman). Section II. Recent Experimental Studies. 9. Molecular thermodynamics of aqueous polymers and gels (H.H. Hooper, H.W. Blanch, and J.M. Prausnitz). 10. Dynamic and equilibrium swelling characteristics of hydrophilic copolymers with carboxylic functional groups (A.R. Khare and N.A. Peppas). 11. Kinetics of swelling of absorbent polymers (F.L. Buchholz). 12. Effect of superabsorber-pulp interactions on the performance of absorbent structures (D.L. Visioli and K.R. Williams). 13. A microstructural analysis of polymer networks formed from graft copolymers in mixed aqueous solvents (C.G. Varelas and C.A. Steiner). Subject Index.

Enzymatic hydrolysis of (di)methacrylates and their polymers

Abstract: Di- and monomethacrylates hydrolyze to methacrylic acid and the alcohol part at neutral pH catalyzed by an unspecific esterase (hydrolase) and by enzymes in saliva. The rate constants of the enzymatic hydrolysis of various (di)methacrylates increase in the following order: HPMA less than BISGMA less than LAMA less than DECMA less than TEGDMA less than UEDMA less than DEGDMA. Esterase added to aqueous slurries of various powders made of polymerized BISGMA/TEGDMA-mixtures gave rise to liberation of methacrylic acid, presumably deriving from degradation of those of the dimethacrylates only bonded in the matrix by one end of the molecule. It was estimated that a TEGDMA-polymer will be hydrolyzed faster than a BISGMA-polymer. It is proposed that hydrolases in saliva increase the wear rate of composite resin fillings.

Flame retardant polymer composition

Abstract: A flame retardant polymer composition which is substantially free of halogen compounds and of organometallic salts comprises (A) an organic polymer, at least 40% by weight of which is a copolymer of ethylene with one or more comonomers selected from the group consisting of alkyl acrylates, alkyl methacrylates, acrylic acid, methacrylic acid and vinyl acetate, (B) a silicone fluid or gum and (C) an inorganic filler which is a compound of a metal of Group II A of the Periodic Table of Elements but which is neither a hydroxide nor a substantially hydrated compound. Suitable inorganic fillers are magnesium oxide, magnesium carbonate and calcium carbonate, the latter being the most preferred. The compositions are particularly suitable for use in wire and cable applications.

Method of making a hydrogel-forming wound dressing or skin coating material

Abstract: The invention disclosed is a hydrogel-forming wound dressing or skin coating material suitable for household and veterinary use, consisting substantially entirely of wound-compatible and skin-compatible ingredients and comprising a first hydrophilic polymer, selected from polymers or copolymers of acrylic acid, polymers or copolymers of methacrylic acid, polymers or copolymers of itaconic acid, polymers or copolymers of maleic acid and polymers or copolymers of 3-butene-1,2,3-tricarboxylic acid, or combinations thereof, a second hydrophilic polymer which is capable of interacting with the first polymer to produce, upon drying, a hydrogel of improved water resistance and film forming properties relative to the first polymer alone and water. This material is film forming and substantially transparent but capable of being made opaque.

Production of acrylic acid and methacrylic acid using Rhodococcus rhodochrous J1 nitrilase

Abstract: e-Caprolactam-induced Rhodococcus rhodochrous J1 cells containing abundant nitrilase were used in the production of acrylic acid and methacrylic acid from acrylonitrile and methacrylonitrile, respectively. Under a periodic substrate feeding system, the highest accumulations, 390 g acrylic acid/l and 260 g methacrylic acid/l, were attained.

Binder for aqueous gloss paints

Abstract: The inventive vehicle, or binder, for water based gloss paints contains, dispersed in a aqueous phase, particles of a multiphase emulsion polymer made up of (a) core material having a glass transition temperature exceeding 40° C. and (b) a shell material having a glass transition temperature of less than 70° C. and at least 20 K. below that of the core material. The particles have an average diameter of less than 200 nm. The composition of the shell material includes an emulsion polymer with at least 4 percent by weight of an ethylenically unsaturated carboxylic acid and more than 80 percent by weight of one or more monomers from the group consisting of styrene and alkyl esters of acrylic and/or methacrylic acid. Paint coats produced with this vehicle are distinguished by a high blocking point.

Oriented multilayer heat sealable packaging film

Abstract: An oriented heat sealable multilayer structure. The structure comprises a substrate having a first surface and a second surface, the substrate comprising a polyolefin film; a polymeric heat sealable layer on the first surface of the substrate, the layer comprising a polymeric material selected from the group consisting of a terpolymer of ethylene, propylene and butene-1, a random copolymer of ethylene and propylene, and blends thereof; a primer coating on the second surface of the substrate; and a water vapor and gas barrier layer on the primer coating, the water vapor and gas barrier layer selected from the group consisting of a vinylidene chloride copolymer containing at least about 50% of vinylidene chloride and an interpolymer comprising a minor amount of acrylic acid, methacrylic acid or mixtures thereof and a major amount of neutral monomer esters comprising methyl acrylate, ethyl acrylate, methyl methacrylate or mixtures thereof. A method for producing the heat sealable multilayer film structure is also provided.

Production of anomalous polymer microspheres having uneven surfaces by “stepwise” heterocoagulation technique

Abstract: Anomalous polymer microspheres having uneven surfaces were produced by “stepwise” heterocoagulation technique of small polymer particles (SPs) onto large polymer particles (LPs).SPs andLPs have surface charges opposite to each other in the emulsion states.SPs were produced by emulsion copolymerization of styrene and methacryloyloxyethyltrimethylammonium chloride, andLPs by emulsion terpolymerization of styrene, butyl acrylate and methacrylic acid, with nonionic emulsifier being used in both cases. Maximum covering ofLP bySPs was obtained under the conditions that both emulsions were blended without the coagulation at pH 3 at room temperature and then left stand to coagulate with each other at 70 °C for 4 h at pH 9.

Process for producing microcapsules

Abstract: In producing microcapsules using the amino resin as a capsule wall in a system in which hydrophobic core material is dispersed or emulsified in an aqueous acidic solution containing an anionic colloidal substance, said anionic colloidal substance comprises an anionic, water-soluble copolymer consisting of at least three monomers including acrylic acid, hydroxyalkylacrylate or hydroxyalkylmethacrylate and styrenesulfonic acid. The process of the present invention provides a good emulsification against the variation of the emulsifying condition, a good stability of emulsion between the encapsulating reaction, an excellent stability against the variation of the encapsulating conditions and a superior capsule slurry. More desirable results may be obtained when an anionic, water-soluble copolymer which is obtained by copolymerizing one or more components selected from alkyl acrylate, methacrylic acid, alkyl methacrylate, acrylamide, methacrylamide, succinic ester of hydroxyalkyl acrylate, succinic ester of hydroxyalkyl methacrylate, vinyl acetate and acrylonitrile as fourth and further components in addition to the above-mentioned three components, is used.

Hydrophilic acrylic copolymers and method of preparation

Abstract: Novel amphoteric acrylic and methacrylic copolymers are described comprising cationic units of pendant N-substituted amidine and anionic units of acrylic or methacrylic acid and/or acidic groups carried by substituents of N-acrylamide, N-methacrylamide, N-acrylamidine or N-methacrylamidine One preferred embodiment is a copolymer in which at least some types of functional groups are organized in blocks Particularly preferred are blocks of pendant nitrile groups Preferred compositions have the said N-substituents of the amides and/or amidines containing polar groups other than primary amines Particularly preferred polar groups are tertiary amines, quaternary ammonium salts, hydroxyls and sulfonic acid These copolymers may optionally be convalently or physically crosslinked and swellable rather than soluble in water A method of preparing said amphoteric acrylic and methacrylic copolymers is described comprising the reaction of selected polymers with a multitude of pendant CN groups in mutual 1,3 positions with a primary amine in presence of water One preferred method is the reaction of CN groups with the primary amine and water in the presence of a solvent of the said polymer and/or in the presence of a basic catalyst The particularly preferred embodiment is a reaction of CN groups containing polymer dissolved in a mixture of the polymer solvent, a primary amine, water and an optional basic catalyst

Kinetics of (CO)polymerizations at the surface of inorganic submicron particles in emulsion-like systems

Abstract: Hydrophilic TiO2 particles were modified with two different titanates and thus made hydrophobic. “Emulsion” polymerizations were carried out in aqueous dispersions of these particles, stabilized with an anionic surfactant. Polymerization kinetics were determined using a densitometer. The effect of several parameters, like surface modification, surfactant and initiator concentration, and stirring speed on polymerizations were studied. Depending on reaction conditions two competitive polymerizations can take place: one in which polymer is formed at the particle surface and one in which free polymer particles are formed. The TiO2 was modified with a titanate containing a methacrylic acid ester, which was used as a comonomer. Thus a chemical bond between TiO2 particles and polymer was obtained. These polymer encapsulated inorganic particles may offer interesting perspectives in those cases, where a good coupling between particles and matrix is important, for instance in latex paints and in polymer composites.

Water-soluble pressure-sensitive skin-adhesive and use thereof

Abstract: A water-soluble salt of a copolymer containing a monoethylenically unsaturated monomer containing amino groups that can be radically polymerized and at least one alkyl ester of acrylic and/or methacrylic acid, is used as a flexible pressure-sensitive adhesive for application to the skin.

Coumarin dyes and side-chain coumarin dye-substituted polymers which exhibit nonlinear optical properties

Abstract: Coumarin dyes such as alkylaminocoumarincarboxamides which have functional hydroxyl groups or which are chemically attached to vinyl monomers such as methacrylic acid. The dyes which are chemically attached to vinyl monomers can be copolymerized, e.g. with acrylic monomers to produce a coumarin dye-containing polymer. The dyes which have functional hydroxyl groups can be reacted with an existing polymer or copolymer, e.g. a copolymer of styrene and acrylic acid to esterify the acid groups of the polymer to form a coumarin dye-containing polymer. Such coumarin dye-containing polymers are formed into films and fibers which when poled in an electric field yield a film or fiber with nonlinear optical properties.

Water clarification through chelation

Abstract: Improved water quality of overboard waters discharged from off-shore oil producing rigs is obtained by treating oily produced waters from a crude oil separator, and prior to exposure to air, with an effective coalescing amount of a combination of an iron chelating agent and various polymeric coagulating/coalescing agents. The preferred chelating agent is citric acid, or its salts, EDTA, HEDTA, or mixtures thereof. The polymeric coagulating/coalescing agents may be anionic, cationic, ampohoteric, but are most preferably copolymers of acrylamide with at least one of the monomers chosen from the group consisting of acrylic acid, methacrylic acid, DMAEA, DMAEM, or their acid of quaternary salts, DADMAC, MAPTAC, AMPS, and the like.

Antimicotic nail varnish containing amorolfine in quaternary ammonium acrylic copolymer

Abstract: An antimycotically-active nail varnish, which contains an antimycotically-active substance selected from 4-[3-[p-(α,α-dimethyl-benzyl)-phenyl]-2-methyl-propyl]-2,6-dimethylmorpholine, 4-[-[p-(1,1,-dimethylpropyl)-phenyl]-2-methyl-propyl]-2,6-dimethyl-morpholine and salts thereof and a water-insoluble film former which a copolymerizate of acrylic acid esters and methacrylic acid esters having a low content of quaternary ammonium groups, is described.

Vapor phase photografting on low‐density polyethylene film in binary monomer systems

Abstract: Vapor phase photografting of monomer mixtures on low-density polyethylene film, on which benzoyl peroxide is coated, was investigated at 60°C using various vinyl, allyl, and solid monomers. Styrene (St) itself was difficult to graft on the film substrate, but the combinations of St with vinyl monomers such as acrylonitrile (AN), glycidyl methacrylate (GMA), acrylic acid, and methacrylic acid led to the accelerated grafting, affording a maximum percent grafting at an certain monomer ratio. The same combination effect was observed for AN–N-vinyl pyrrolidone and –GMA monomer mixtures. The monomer combinations such as allyl aldehyde–St and allyl alcohol–maleic anhydride were useful for performing the grafting of allyl monomers effectively. Maleic anhydride and maleimide as solid monomers were also possible to introduce into the film substrate by means of the monomer combination, where St, N-vinyl pyrrolidone, vinyl ethers, and benzyl methacrylate were available as comonomers. Thus, the monomer combinations affording an accelerating effect on grafting may be monomer pairs rich in an alternative copolymerizability, suggesting that monomer reactivity ratio controls a major factor for the combination effect. It was confirmed from IR study on grafted films that both monomer components are introduced in the film substrate as the grafted chain component.

Emulsifier-free emulsion polymers for pharmaceuticapreparations

Abstract: An emulsion polymer which has been treated with an extractant in which the emulsion polymer is not soluble and thus freed from emulsifiers and surfactants and other auxilliaries soluble in the solvent, is new. The emulsion polymer which can serve as a carrier (or sustained release pharmaceuticals is based on methyl and/or ethyl esters of acrylic and/or methacrylic acid, or consists of poly-lactide, polystyrene, polyvinylacetate, polyvinyl-pyrrolidone, polybutadiene, polyacrylonitrile, etc..

Nonionically and partially anionically stabilized waterdispersible graft copolymers

Abstract: Water-dilutable polyurethane/acrylic copolymers which may be either completely nonionically stabilized or partially nonionically and partially anionically stabilized comprise the reaction product of an ethylenically terminated polyurethane macromonomer containing poly(oxyalkylene) segments and one or more ethylenically unsaturated monomers selected from acrylic acid, methacrylic acid, fumaric acid, styrene, vinyltoluene, and alkyl and hydroxyalkyl esters of acrylic, methacrylic, and furamic acids. The copolymers are useful as principal resins and as pigment grind resins in water-borne automotive base coat paint formulations.

Proposal for Active Sites of Iron Phosphates In Isobutyric Oxidative Dehydrogenation Reaction

Abstract: Iron phosphate based catalysts are claimed to be active and selective for the oxidative dehydrogenation of isobutyric acid to methacrylic acid In order to progress in the knowledge of these catalysts we have synthesized, studied as catalyst and characterized well defined phases in the ternary phase diagram Fe2O3 - FeO - P2O5 The characterization by RGN and XRD of the samples before and after catalysis shows that the starting phases were transformed under the conditions of reaction and that a new phase was formed containing both ferric and ferrous ions in the same framework which should favor, through easier electron transfer, a redox type mechanism This phase which has also been identified in industrial catalyst could be responsible for the high performances of the latter

Coating composition of an acrylic polymer, a crosslinking agent and a silane oligomer

Abstract: A high solids coating composition useful as a clear coat for an automotive clear coat/color coat finish which contains about 40-80% by weight of a binder and correspondingly about 20-60% by of a liquid organic carrier; wherein the binder contains about: a. an acrylic solution polymer of polymerized monomers of ethylenically unsaturated esters of acrylic acid or methacrylic acid and a hydroxy alkyl acrylate or methacrylate and the polymer has a hydroxyl no. of about 50-200 and a weight average molecular weight of about 4,000-20,000; b. a dispersed polymer of polymerized monomers having stabilizer resin segment that is soluble in the organic carrier and dispersed resin segment that is relatively insoluble in the organic carrier; c. a siloxane oligomer having --OH and --OR groups attached to the silane atoms of the oligomer where R is an alkyl group having 1-6 carbon atoms in the alkyl group or an aryl group and the oligomer has a weight average molecular weight of about 500-5,000; and d. an alkylated melamine formaldehyde resin.