Showing papers on "Methacrylic acid published in 1993"

Recognition sites incorporating both pyridinyl and carboxy functionalities prepared by molecular imprinting

Abstract: Noncovalent molecular imprinting using simultaneously two chemically distinct functional monomers, namely the weedy basic 2-vinylpyridine and the acidic and hydrogen bonding methacrylic acid, war demonstrated in ethylene glyool dimethacrylate bared copolymers. Terpolymerizations of this type were shown to be particularly useful for the preparation of imprints against carboxylic acids, which additionally contained a complex array of other chemical functionalities. Such imprinted polymers demonstrated improved recognition capabilities as compared with polymers which were prepared using only one of the functional monomers

Hybridization of Block Copolymer Micelles

Abstract: : Block copolymers of styrene and methacrylic acid dissolved in water/ dioxane mixtures form spherical micelles with polystyrene cores and poly(methacrylic acid) shells. When two micellar solutions containing micelles made from two different copolymers are mixed, the micelles may hybridize. The hybridization was followed by the method of sedimentation velocity. The rate of hybridization was found to be a very sensitive function of the architecture of both copolymers and of the thermodynamic properties of the solvent mixture. In many instances this rate is imperceptible slow; it may be totally frozen when the solvent is very poor with respect to the micellar core. The analysis of the hybridization of numerous micellar pairs provided new insights into the dynamics and thermodynamics of unimer/micelle equilibria. (Author)

Polymers of biological and biomedical significance

Abstract: Polymers in Pharmaceutical Products Tissue Engineering Using Synthetic Biodegradable Polymers Interfacial Biocompatibility Polymeric Devices for Transcutaneous and Percutaneous Transport Microcellular Foams Surface Biolization by Grafting Polymerizable Bioactive Chemicals Hydrophilic, Lipid-Resistant Fluorosiloxanes Synthesis of Poly(ether urethane amide) Segmented Elastomers Interaction of Water with Polyurethanes Containing Hydrophilic Block Copolymer Soft Segments Formation and Reactivity of Surface Phosphonylated Thermoplastic Polymers Surface Modification of Polymeric Biomaterials with Poly(ethylene oxide): A Steric Repulsion Approach Ascorbic Acid as An Etchant-Conditioner for Resin Bonding to Dentin Salt Partitioning in Polyelectrolyte Gel-Solution Systems Ring-Opening Polymerization of a 2-Methylene Spiro Orthocarbonate Bearing a Pendant Methacrylate Group Ring-Opening Dental Resin Systems Based on Cyclic Acetals Synthesis of Novel Hydrophilic and Hydrophobic Multifunctional Acrylic Monomers Effect of Structure on Properties of Absorbable Oxalate Polymers Fluorescent Cure Monitoring of Dental Resins Activation of Leukocytes by Arg-Gly-Asp-Ser-Carrying Microspheres Poly(vinyl alcohol) Hydrogels Prepared under Different Annealing Conditions and Their Interactions with Blood Components Phase Transition's Control of Collagenous Tissue Growth and Resorption Including Bone Morphogenesis pH-Sensitive Hydrogels Based on Hydroxyethyl Methacrylate and Poly(vinyl alcohol)-Methacrylate Kinetic Model for Degradation of Starch-Plastic Blends with Controlled-Release Potential Cross-Linking and Biodegradation of Native and Denatured Collagen Poly(methacrylic acid) Hydrogels as Carriers of Bacterial Exotoxins in an Oral Vaccine for Cattle Dye-Grafted, Poly(ethylene imine)-Coated, Formed-in-Place Class Affinity Membranes for Selective Separation of Proteins Preparation of Insulin-Releasing Chinese Hamster Ovary Cell by Transfection of Human Insulin Gene: Its Implantation into Diabetic Mice pH and Ionic-Strength-Dependent Permeation through Poly(L-lysine-alt-terephthalic acid) Microcapsule Membranes Rg-Gly-Asp-Ser-Carrying Microspheres

Acrylonitrile-acrylic acids copolymers. I: Synthesis and characterization

Abstract: Acrylonitrile (AN) was copolymerized with acrylic acid (AA), methacrylic acid (MAA), and itaconic acid (IA) by the aqueous suspension method at 40°C with ammonium persulfate and sodium metabisulfite as the redox initiator. The reactivity ratios for the AN–AA and AN–IA systems were also calculated by the Finemann–Ross and the Kelen–Tudos methods. Higher r2 (AA) for the AN–AA system in comparison to r2 (IA) for the AN–IA system indicates greater reactivity of AA toward the propagating species. The influence of co-monomers on intrinsic viscosity, tacticity, and number-average sequence lengths was studied. 13C-NMR spectra revealed that AN copolymers having approximately 2 mol % of AA have a greater percentage (>30%) of isotactic content than of homopolyacrylonitrile. Tacticity has also been calculated from infrared spectra of the polymers using stereospecific absorption bands at 1250 and 1230 cm−1. © 1993 John Wiley & Sons, Inc.

Protein adsorption and platelet adhesion onto polyurethane grafted with methoxy‐poly(ethylene glycol) methacrylate by plasma technique

Abstract: Graft polymerization of methoxy-poly(ethylene glycol) methacrylate, an ester of methacrylic acid and monomethoxy-poly(ethylene glycol) (PEO), was performed onto a polyetherurethane (PU) film and tube under different polymerization conditions by a plasma treatment technique. The surface of grafted PU film was characterized by staining with dye, x-ray photoelectron spectroscopy, contact angle, and zeta potential. All these measurements indicated that water-soluble chains were immobilized on the PU surface, their location being restricted to the film surface region. The PU surface showed reduced protein adsorption in vitro and reduced platelet adhesion in vitro and ex vivo. The optimum graft density suppressing the protein adsorption was as low as 5 μg cm−2. When a small amount of dimethacrylate was added to the monomer solution for graft polymerization to introduce crosslinking in the grafted layer, protein adsorption was further slightly reduced. The extent of reduction in serum albumin adsorption was always less than that of γ-globulin. Although platelet adhesion was largely reduced by the surface graft polymerization, a definite amount of protein was always adsorbed to the grafted surface. © 1993 John Wiley & Sons, Inc.

Influence of Aging on the Physical-Mechanical Properties of Acrylic Resin Films Cast from Aqueous Dispersions and Organic Solutions

Abstract: The physical-mechanical properties of the enteric copolymers, poly(methacrylic acid, ethyl acrylate) Eudragit® L100-55, and Eudragit® L30D have been investigated. Free films of the copolymer containing varying levels of glyceryl triacetate (triacetin) and citrate ester (Citroflex®) plasticizers were prepared by both aqueous and solvent casting techniques. Conditioned films were stored at different humidities and temperatures for predetermined time periods prior to testing. Free films with plasticizer concentration ranging from 0 to 30% by weight of the polymer demonstrated that physical aging at room temperature resulted in physical-mechanical changes as the stress-strain curves indicated a decrease in the percent elongation with increases in the tensile strength. Films prepared from the aqueous latex approached a constant state of equilibrium at a faster rate than films prepared from isopropyl alcohol, where the mechanical properties approach a relatively constant value. Free films containing var...

Metal Ion-Selective Adsorbent Prepared by Surface-Imprinting Polymerization.

Abstract: We propose a metal ion-imprinted microsphere as a new metal ion-selective adsorbent Imprinted microspheres were prepared by seeded emulsion polymerization of divinylbenzene, styrene, butyl acrylate, and methacrylic acid The imprinted structure was introduced on the carboxylated microsphere by surface-imprinting, in which the carboxyl groups were reorganized through complexation with metal ions on the surface and then fixed by crosslinking polymerization in their specific orientation The Cu(II), Ni(II), and Co(II)-imprinted microspheres were obtained as submicron particles with average diameters of 055—060 μm They were immediately used as a metal ion-selective adsorbent without any further treatment, such as grinding and sieving The adsorption behaviors of metal ions (Cu(II), Ni(II), and Co(II)) were examined, and the imprinted effects were verified on Cu(II)- and Ni(II)-imprinted microspheres The imprinted microspheres adsorbed the corresponding guest ion more effectively than did unimprinted ones

High-resilience ionomeric compositions for golf ball covers

Abstract: Ionomers derived from ethylene/methacrylic acid or ethylene/acrylic acid copolymers, containing high levels of acid neutralized with lithium, zinc and sodium are blended in defined amounts to form compositions with very high resilience. The compositions are highly suitable for use as golf ball covers.

Longitudinal modulus and hydraulic permeability of poly(methacrylic acid) gels: effects of charge density and solvent content

Abstract: The equilibrium longitudinal modulus, hydraulic permeability, and fixed charge density of poly(methacrylic acid) gels were measured over a wide range of pH, ionic strength, and uniaxial strain (solvent content). Mechanical measurements were performed using a compression stress relaxation procedure which was analyzed in the context of a poroelastic theory of gel swelling kinetics. The longitudinal modulus varied with ionization state and solvent content in a manner that suggests the importance of ionized charge density as a critical determinant of gel stiffness and swelling. The modulus decreased while the hydraulic permeability increased substantially with increasing gel solvent content

High temperature aqueous polymerization process

Abstract: This invention relates to high temperature aqueous processes for the polymerization of monoethylenically unsaturated carboxylic monomers to produce low molecular weight, water-soluble polymer products useful as detergent additives, scale inhibitors, dispersants and crystal growth modifiers. Suitable monomers include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, crotonic acid, and itaconic acid. The reactions are run at temperatures ranging from about 130° C. to 240° C., preferably from about 140° C. to about 230° C. The process can be continuous, semi-continuous, or batch.

Enteric coated soft capsules and method of preparation thereof

Abstract: Soft capsules coated with an enteric coating comprising a 1:1 copolymer of methacrylic acid and methyl or ethyl acrylate or methyl or ethyl methacrylate and a plasticizer without need for a subcoating and optionally additionally coated with a protective coating comprising hydroxypropyl methylcellulose or hydroxypropyl cellulose or a mixture thereof and a plasticizer and method of preparation thereof are disclosed.

Golf ball cover having an ionic copolymer/non-ionic copolymer blend

Abstract: The present invention is directed to a golf ball cover comprising a blend of copolymers wherein one or more of the copolymers is a low cost nonionic copolymer and one or more of the copolymers is an ionic copolymer. Surprisingly, a golf ball cover comprising the non-ionic/ionic copolymer blend exhibits no loss in C.O.R., and has equal resistance to cutting and cracking when compared to top grade golf ball covers made with one of the conventional 100% ionic copolymer blends. In particular, the present golf ball cover comprises from about 95 to about 80 pphr of one or more ionic copolymers, and from about 5 to about 20 pphr of one or more non-ionic copolymers, the latter being selected from the group consisting of a copolymer of ethylene and acrylic acid, a copolymer of ethylene and methacrylic acid, a copolymer of polypropylene and acrylic acid, a terpolymer of ethylene, acrylic acid and a lower alkyl acrylate, and a terpolymer of ethylene, methacrylic acid and a lower alkyl acrylate, and blends thereof.

Cement set retarding additives, compositions and methods

Abstract: The present invention provides set retarding additives, set retarded hydraulic cement compositions including such additives and methods of using the cement compositions for cementing zones in wells. The set retarding additives are graft copolymers or terpolymers comprised of the condensation polymer product of a ketone, aldehyde and a compound which introduces acid groups into the polymer having grafted thereto a monomer selected from the group consisting of acrylic acid, vinyl phosphonic acid, methacrylic acid, maleic acid and itaconic acid or one of the foregoing monomers and a second monomer of 2-acrylamido-2-methylpropane sulfonic acid.

Synthetic pH sensitive polyampholyte hydrogels: A preliminary study

Abstract: A combined capillary drop viscometer-pH cell has been constructed and used to study the solution properties of some polymeric weak acids, bases, and ampholytes containing methacrylic acid (MAA), dimethylaminoethyl methacrylate (DMAEMA), and 2-hydroxyethyl methacrylate (HEMA). The behavior of polyelectrolytes based on MAA or DMAEMA is consistent with established thinking, and is dominated by the chain expansions which accompany ionization of acidic (MAA) or protonation of basic (DMAEMA) functionality. The solution behavior of the polyampholytes is complex and was studied as a preliminary to investigations of crosslinked hydrogel analogues. Briefly, it was found that changes in polymer coil dimensions were dictated by the formation or “breakage” of intramolecular salt bridges by, for example, lowering the solution pH to protonate weakly acidic, or raising the pH to deprotonate weakly basic functionality. Similar effects were observed on adding counterions which preferentially complex with one of the bound ions. The pH “sensitivity” of polymer coil dimensions increased with the concentration of charged functionality in the polymer. Chemically crosslinked polyampholytes were prepared and equilibrium water contents were measured as a function of pH. In contrast, due to network constraints, the pH “sensitivity” of the hydrogels, as measured by changes in equilibrium water uptake, increased with a decrease in the level of charged functionality in the polymer.

Polymeric surfactant and latex made therefrom

Abstract: A polymeric surfactant comprises the reaction product of ethylentcally unsaturated monomers at least 40 percent by weight of which are acid group containing monomers, including a combination of both acrylic acid and methacrylic acid, at least a portion of the acid groups being neutralized by a base. Also disclosed is an aqueous acrylic latex made by polymerizing a second polymer from ethylenically unsaturated monomers in the presence of said polymeric surfactant, whereby the latex comprises polymeric particles containing two polymers. The latex may be used to advantage in very low V.O.C. coatings that may be spray applied.

Surface and interfacial FTIR spectroscopic studies of latexes. IV. The effect of surfactant structure on the copolymer–surfactant interactions

Abstract: The interactions between sodium dodecylbenzene sulfonate (SDBS) and the components of an ethyl acrylate/methacrylic acid (EA/MAA) copolymer latex were examined and the influences of using D2O as the synthetic suspension medium were investigated. Whereas it is found that D2O has no detectable influence on the fully coalesced latex films, the film coalescence conditions are shown to significantly affect the nature of surfactant interactions within the film matrix. When films are prepared and stored under controllable low atmospheric water-vapor concentrations, hydrogen-bonding interactions between the surfactant SO3−Na+ groups and the copolymer acid functionality dominate. However, coalescence and storage of the films under higher relative humidity conditions results in a displacement of these interactions in favor of the hydrated form of the surfactant. It is also shown that the presence of an aromatic ring adjacent to the surfactant sulfonate group exerts an influence on the nature of the SO3− ··· HOOC interactions within the copolymer matrix. Relative to sodium dioctyl sulfosuccinate (SDOSS), the aromatic group near hydrophilic end of SDBS increases the strength of the SO bond in the presence of acid interactions. © 1993 John Wiley & Sons, Inc.

Removable, hard, durable, nail coating

Abstract: A photocurable coating composition to be applied directly onto a nail surface and is rapidly curable upon exposure to ultraviolet light, comprising between 5% and 65% by weight of a film-forming polymer selected from the group consisting essentially of: i) cellulose derivatives ii) acrylic polymers; between 2% and 20% by weight of a photoinitiator selected from the group consisting essentially of: i) acetophenone ii) benzophenone iii) alkylphenyl ketone iv) cyclohexylphenyl ketone; and between 10% and 90% by weight of a photoreactive monomer selected from the group consisting essentially of: i) methacrylic acid esters ii) diesters of methacrylic acid, where the percentages by weight are based on the composition total weight.

Temperature Dependence of Viscosities and Potentiometric Titration Behavior of Aqueous Poly(acrylic acid) and Poly(methacrylic acid) Solutions

Abstract: Temperature Dependence of Viscosities and Potentiometric Titration Behavior of Aqueous Poly(acrylic acid) and Poly(methacrylic acid) Solutions

Surface and interfacial FTIR spectroscopic studies of latexes. V. The effects of copolymer composition on surfactant exudation

Abstract: The influence of copolymer structure on the magnitude of surfactant enrichment to the film—air and film—substrate interfaces of latex films prepared on a polytetrafluoroethylene (PTFE) substrate is investigated. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR) is used to elucidate the surfactant enrichment by the comparison of butyl acrylate/methyl methacrylate/methacrylic acid (BA/MMA/MAA) and ethyl acrylate/methacrylic acid (EA/MAA) latex systems prepared with various anionic surfactants. It is found that, in all cases, the magnitude of exudation of the sulfonate-containing surfactants manifested by the presence of S—O bending and scissors modes is reduced in the case of the BA/MMA/MAA latex. Similar behavior is observed when the spectra of films prepared on a liquid mercury substrate are compared. It is believed that this behavior results from the longer aliphatic n-butyl groups present in this copolymer that enhances compatibility by providing a greater opportunity for hydrophobic surfactant—copolymer interactions. The butyl groups may also reduce excess interfacial free energy by orienting themselves toward the film interfaces, which, in turn, will reduce the surface tension-induced driving force for surfactant exudation. © 1993 John Wiley & Sons, Inc.

Biodegradable polyethylene composition chemically bonded with starch and a process for preparing thereof

Abstract: The present invention relates to a biodegradable film prepared by chemical bonding of starch and polyethylene chains using polyethylene, which is polyolefin having the most widest general application, coupling agent such as maleic anhydride, methacrylic anhydride or maleimide which bonds with starch and polyethylene, and acid catalytic comonomer like acrylic acid and/or methacrylic acid and to a process for preparing thereof. The present invention was accomplished varying coupling agent such as maleic anhydride, methacrylic anhydride or maleimide at an amount of 0.01-10 weight %, acid catalytic comonomer such as acrylic acid and/or methacrylic acid at an amount of 0.01-10 weight % and radical initiator at an amount of 0.01 1.0 weight % based on the amount of polyethylene, and the reactive extrusion was appelied to lower the production cost by process simplification. There was no difference in tensile strength and tensile elongation of the prepared biodegradable films comprising up to 20 wt. % of starch in comparison with the base resin by Instron measurement. The facts that ester bond showing chemical bonding between starch and matrix resin was found on the infrared absorption spectrum and the phenomenons that the boundary between matrix resin and starch particle is unclear, and the starch particle is cross-sectionally cut are shown on the cross-section of films with scanning electron microscope approving chemical bonding between starch and matrix. The biodegradability was the most excellent with more than 10 wt. % of starch.

Silica supported metal-doped cesium ion catalyst for methacrylic acid synthesis via condensation of propionic acid with formaldehyde

Abstract: Various metal oxides such as Bi, La, Pb, Tl and W were doped onto the silica supported Cs + catalyst, and the effect of these dopants on the catalyst performance (activity and stability) of the Cs + /SiO 2 catalyst was studied for the synthesis of methacrylic acid by the vapor condensation reaction of propionic acid with formaldehyde. Among the catalysts studied, the Bi-doped catalyst, Cs/Bi/SiO 2 , has shown the best catalyst activity and selectivity for methacrylic acid, and, in particular, has demonstrated improved catalyst aging stability over the Cs + /SiO 2 catalyst.

Infrared Spectral Change in a Zinc Salt of an Ethylene-Methacrylic Acid Ionomer on Water Absorption.

Abstract: Infrared Spectral Change in a Zinc Salt of an Ethylene-Methacrylic Acid Ionomer on Water Absorption

Process for the preparation of acrylic polymers for pharmaceutical coatings

Abstract: Provided is a process useful for preparing acrylic polymers of methacrylic acid and ethyl acrylate. The process provides polymers useful as enteric coatings for medicaments in solid form, said coatings having improved effectiveness, reproducibility and coating efficiency. Also provided are medicaments in solid form coated with such polymers.