Showing papers on "Acrylic acid published in 1991"

Handbook of polymer synthesis

Abstract: Polyefins. Polystyrenes and Other Aromatic Poly(Vinyl Compounds). Poly(vinyl ehters)s Poly (vinyl ester)s, and Poly (vinyl halogenide)s. Polymers of Acrylic Acid, Methacrylic Acid, Maleic Acid, and Their Derivatives. Polymeric Dienes. Metathesis Polymerization of Cycloolefins. Aromatic Polyethers. Polyurethanes. Polymides. Poly(vinyl aldehyde)s, Poly(vinyl ketone)s, and Phosphorous-Containing Vinyl Polymers. Metal-Containing Macromolecules. Electrically Conducting Polymers. Photoconductive Polymers. Polymers for Organic Light Emitting Devices/Diodes (OLEDS). Crosslinking and Polymer Networks. Biodegradable Polymers for Biomedical Applications. Controlled/Living Radical Polymerization.

Materials for enhancing cell adhesion by immobilization of cell-adhesive peptide

Abstract: Materials to enhance cell adhesion were synthesized by surface integration of peptide, Arg-Gly-Asp-Ser(RGDS), which is an active-site sequence of cell-adhesive proteins. Polystyrene film was glow-discharged and graft-copolymerized with acrylic acid. Then the peptide was immobilized to the poly(acrylic acid) grafts by using water-soluble carbodiimide. The cell-adhesive activity of the RGDS-immobilized film increased with increasing amount of immobilized peptide, and approached the activity of fibronectin(FN)-immobilized film. The RGDS-immobilized film was more stable against heat treatment and pH variation than the FN-immobilized film. In addition, the RGDS-immobilized film enhanced cell growth more strongly than the FN-immobilized film.

Water soluble derivatives of taxol

Abstract: Sulfonated 2'-acryloyltaxol and sulfonated 2'-O-acyl acid taxol derivatives are synthesized which have improved water solubility and stability while maintaining bio-activity. In particular, 2'-[(3-sulfo-1-oxopropyl)oxy]taxol sodium salt is synthesized by reacting taxol with acrylic acid, and subsequently reacting the 2'-acryloyltaxol with bisulfite in a Michael reaction. 2'-{[4-((2-sulfoethyl)amino)-l,4-dioxobutyl]oxy} taxol sodium salt and 2'-{[4-((3-sulfopropyl)amino)-1,4-dioxobutyl]oxy} taxol sodium salt are synthesized by reacting 2'-succinyltaxol with the tetrabutylammonium salts of taurine and 3-aminopropyl sulfonic acid, respectively, and subsequently exchanging the ammonium with sodium. Glycol derivatives of 2'-O-acyl acid taxols with improved water solubility are synthesized by reaction of a glycol with 2'-O-acyl acid taxol.

Novel colloidal polyaniline fibrils made by template guided chemical polymerization

Abstract: The colloidal fibrils of polyaniline–poly(acrylic acid) complex were first synthesized by template guided chemical polymerization; their morphology and the electronic absorption spectra in aqueous solution are reported.

Environmentally Sensitive Polymers and Hydrogels

Abstract: Environmentally sensitive polymers and hydrogels exhibit sharp changes in behavior in response to relatively small changes in conditions such as temperature or pH. Typical changes include precipitation of the polymer in water or collapse of a hydrogel with expulsion of a large fraction of the gel pore water. These changes are depicted in Figure 1. If such a polymer is grafted or adsorbed on another polymer surface or within the pores of a porous membrane, then one observes sharp changes in wettability or permeability, respectively, when the polymer is environmentally stimulated. These changes are usually reversible, although the recdissolution or reswelling processes are often slower than the precipitation or deswelling steps. Other examples of environmental stimuli and polymer system responses are listed in Tables I and II. A large number of polymers display sharp responses to such stimuli. Many are based on vinyl monomers, such as anionic and cationic monomers for pH, specificion, solvent, or electrically responsive systems, and N-alkyl substituted acrylamides (e.g., N-isopropyl acrylamide, or NIPAAm) for temperature-sensitive systems. Other copolymer compositions may contain the responsive moiety as a pendant group on one of the monomers. Photoresponsive groups have been incorporated in such a way. The ratio in the responsive polymer of the responsive monomeric component to the “nonresponsive” comonomer (e.g., the pH-sensitive monomer, acrylic acid, versus acrylamide or the temperature-sensitive monomer, NIPAAm versus acrylamide) will control both the sharpness and intensity of the response as well as the specific environmental conditions where it begins.

Complexation of acrylic acid copolymers with polybases: importance of cooperative effects

Abstract: The formation of polymer complexes was studied between poly(ethylene oxide) (PEO) and poly(N-vinylpyrrolidone) (PVP), as hydrogen-bond acceptors and copolymers of acrylic acid (AA) with vinylsulfonic acid (VS) or with 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as hydrogen-bond donors. Under acidic conditions (e.g., pH≃3), the strong-acid groups (VS or AMPS) are dissociated and uncomplexable, while the carboxylic groups (COOH) can be complexed by the polybase (PEO or PVP). Potentiometric and viscometric studies showed that the properties and the structure of the complexes formed depend on the experimental parameters: molar content of sulfonated monomers, concentration of polyacid and polybase, molecular weight of polymers, and nature of polybase

Water-soluble polymer sensitive to salt

Abstract: A water-soluble polymer which is soluble in tap water, but insoluble in an aqueous solution containing 05% or more of a neutral inorganic salt, which is a copolymer of: (A) 30 to 75% by weight of acrylic acid, (B) 5 to 30% by weight of a vinyl monomer represented by the following general formula [1]: CHsub2 ═C(R)COORsup1 [1] wherein R represents a hydrogen atom or a methyl group; and R 1 represents an alkyl group having 8 to 12 carbon atoms, and (C) 20 to 40% by weight of a vinyl monomer represented by the following general formula [2]: CHsub2 ═C(Rsup2)COORsup3 [2] wherein R 2 represents a hydrogen atom or a methyl group; and R 3 represents an alkyl group having 2 to 4 carbon atoms and in which not more than 50 molar % of the repeating units of derived from the acrylic acid is in the form of a salt When the polymer is used as a binder for a non-woven fabric or paper, it exhibits satisfactory strength and permeability to a body fluid when the resultant product is wet with body fluid

Polymer-polymer complexation in dilute aqueous solutions: poly(acrylic acid)-poly(ethylene oxide) and poly(acrylic acid)-poly(vinylpyrrolidone)

Abstract: Fluorescence spectroscopy of pyrene-labeled poly(acrylic acid) (P AA) was used to study its interactions with poly (ethylene oxide) (PEO) and poly(vinylpyrrolidone) (PVP) in aqueous solutions. The effects of molar ratio. molecular weight, and solvent were also investigated. Hydrogen bonding is the primary mechanism of interaction among these polymers. Excimer fluorescence studies show that the PVP-P AA complex is stronger than and exists in a more constricted form than the PEo-P AA complex. Interactions between PVP and PAA are prevalent over a wider pH range than those of PAA and PEa. The higher electronegativity of the oxygen in the pyrrolidone group is attributed as the reason for the stronger interaction of PVP with poly(acrylic acid).

Production of esters of lactic acid, esters of acrylic acid, lactic acid, and acrylic acid

Abstract: Processes are disclosed for producing lactic acid, esters of lactic acid, acrylic acid, and esters of acrylic acid, primarily from fermentable carbohydrate materials. An overall process for producing esters of acrylic acid comprises: a) fermenting carbohydrate material with a lactic-acid-forming organism in the presence of NH 3 to produce ammonium lactate; b) combining the ammonium lactate with an alcohol; c) combining the ammonium lactate and alcohol with an effective catalyzing amount of gaseous CO 2 to catalytically esterify the ammonium lactate and alcohol into a lactic acid ester containing solution; d) recovering purified lactic acid ester; and e) vaporizing the lactic acid ester and passing it through a solid catalyst bed comprised of an effective catalyzing amount of crystalline hydrated and partially calcined calcium sulfate to catalytically convert lactic acid ester into an acrylic acid ester. Step "d" would be useful in a process for making low-cost, purified lactic acid. Similarly, step "e" would be useful in a process for making low cost, purified acrylic acid.

Structure and properties of partially neutralized poly(acrylic acid) gels

Abstract: We investigated, using small-angle neutron scattering, the effect of the charge density on the polymer chains of polyacrylic acid gels. The structure factor was found to have a peak at a finite wavevector q*. The position and the amplitude of this peak depend on the polymer concentration, the charge density on the chains and the ionic content of the solvent. The results obtained are fairly well understood with the advent of recent theoretical studies [1, 2], in which it is shown that such materials are liable to form mesophases at a microscopic scale.

Superabsorbent Crosslinked Ampholytic Ion Pair Copolymers

Abstract: The present invention provides crosslinked ampholytic copolymers that are highly absorbent to aqueous electrolyte solutions. The polymers of the present invention comprise polymers formed by the copolymerization of an effective amount of each of the following components to produce a polymer which is highly absorbent to aqueous electrolyte solutions: (a) an ampholytic ion pair monomer comprising (i) the ammonium cation 2-methacryloyloxyethyldimethylammonium and (ii) a sulfonate anion selected from the group consisting of 2-acrylamido-2-methylpropane sulfonate, 2-methacryloyloxyethane sulfonate, vinyl sulfonate, styrene sulfonate and any combination of two or more therof: (b) at least one comonomer selected from the group consisting of acrylamide, methacrylamide, acrylonitrile, acrylic acid, methacrylic acid, alkali salts of acrylic acid, alkali salts of methacrylic acid, 2-methacryloyloxyethyldimethylamine, 2-acrylamido-2-methylpropane sulfonic acid, alkali salts of 2-acrylamido-2-methylpropane sulfonic acid, 2-methacryloyloxyethane sulfonic acid, alkali salts of 2-methacryloyloxyethane sulfonic acid, N-vinyl-2-pyrrolidone and any combination of two or more thereof;and (c) at least one crosslinking agent which has at least two polymerizable olefinic functionalities wherein the olefinic functionalities are suitable for crosslinking. The invention also provides a method of using the polymers of the present invention for absorbing an aqueous electrolyte solution comprising the step of contacting the polymers of the present invention with the aqueous electrolyte solution.

Fluorescence and viscometry study of complexation of poly(acrylic acid) with poly(acrylamide) and hydrolysed poly(acrylamide)

Abstract: Interpolymer complexation of poly(acrylic acid) with poly(acrylamide) and hydrolysed poly(acrylamide) was studied by fluorescence spectroscopy and viscometry in dilute aqueous solutions. Changes in chain conformation and flexibility due to the interpolymer association are reflected in the intramolecular excimer fluorescence of pyrene groups covalently attached to the polymer chain. Both poly(acrylamide) and hydrolysed poly(acrylamide) form stable complexes with poly(acrylic acid) at low pH. The molecular weight of poly(acrylic acid) and solution properties such as pH and ionic strength were found to influence the stability and the structure of the complexes. In addition, the polymer solutions mixing time showed an effect on the mean stoichiometry of the complex. The intrinsic viscosity of the solutions of mixed polymers at low pH suggested a compact polymer structure for the complex.

Water treatment agent

Abstract: Unsaturated compounds which can be dissolved in aqueous based solvents, such as ethylenic or acetylenic carboxylate or alcohols with less than 10 carbon atoms, especially maleic and/or acrylic acid or propargyl alcohol, are reacted with alkali metal phosphite in aqueous solution at neutral or alkaline pH in the presence of free radical initiators such as persulphate to form threshold scale and corrosion inhibitors.

Polyacrylic acid compositions for textile processing

Abstract: Novel polyacrylic acid resins are prepared by polymerizing H2C=CHCO2H, H2C=CRCO2X, or HRC=CHCO2X, wherein R is an aliphatic or aromatic hydrocarbon, halogenated hydrocarbon, or sulfonated hydrocarbon of from C1 to C20, phenol, naphthol, sulfonated phenol, sulfonated naphthol, or a halogen, and X is hydrogen, alkyl, or a hydroxylated, ethoxylated, sulfonated, or halogenated aliphatic or aromatic hydrocarbon of from C1 to C20, sodium, potassium, ammonium, or quaternary amine, in the presence of aromatic sulfonic acid or its salt to form a polymer in which the sulfonated aromatic compound is covalently bound to the polymer. In an alternative embodiment, a textile processing or cleansing compound is included in the polymerization reaction along with the acrylic acid and aromatic sulfonic acid or its salt. The resulting polymers have superior properties for use in textile processing and cleaning, and can be used as detergents, acid dye levelers, surfactans, emulsifiers, yarn lubricants, copolymerizing agents, polymer after treat agents, defoamers, chelating agents, flocculants, anti-static agents, flame retardants, metal cleaners, metal coatings, and as multipurpose acids.

Hydrophilic pressure sensitive adhesive for topical administration of hydrophobic drugs

Abstract: Novel hydrogel formulations useful as adhesive reservoirs for topical or transdermal drugs employ as the polymer base a crosslinked polymer or copolymer of 2-acrylamido-2-methylpropane sulfonic acid or a salt thereof. The gels are prepared from polymerizable compositions comprising: 20 % - 50 % of a monofunctional monomer component, at least 75 % of said component comprising 2-acrylamido-2-methylpropane sulfonic acid or a salt thereof, the balance being selected from the group consisting of acrylic acid, water soluble acrylic functional monomers and vinyl pyrrolidone; 30 % - 50 % of a glycol component selected from the group consisting of compounds of the formula: HO-(C2H4O)n-H, HO-(C3H6O)m-H and mixtures thereof, where n is in the range of about 4 to about 16 and m is 1-4; between about 0.02 % and about 0.20 % of a crosslinking monomer; an amount of a free radical polymerization initiator effective for initiating polymerization of said monofunctional monomer and crosslinking monomer components; and a therapeutically effective amount of a topically or transdermally deliverable drug, at least about 60 % of said drug being dissolved in the formulation.

Graft copolymerization of vinyl monomers onto chitin with cerium (IV) ion

Abstract: Graft copolymerization of vinyl compounds onto chitin was studied, and an efficient and reproducible procedure has been established, cerium (IV) being used as the initiator. The reactions with acrylamide and acrylic acid onto powdery chitin were carried out under various conditions to elucidate the polymerization behavior in terms of grafting percentage. The amount of cerium (IV) affected the polymerization most strikingly, and grafting percentages showed maxima with suitable amounts of initiator for both the monomers. As a solvent water proved to be superior to aqueous nitric acid except the reaction with a small amount of initiator. Under appropriate conditions, around 240 and 200% grafting percentages were achieved for acrylamide and acrylic acid, respectively. The resulting graft copolymers showed much improved affinity for solvents and hygroscopicity compared to the original chitin.

Interaction between calcium, a model divalent cation, and a range of poly(acrylic acid) resins as a function of solution ph

Abstract: The interaction between calcium, a small divalent cation, and selected polyacrylic acid polymers has been studied. The addition of calcium chloride to dispersions of the polymer reduced the maximal viscosity through an interaction which was not dependent upon physical entrapment of the cation by the viscous medium. The binding interaction between the cation and the polymer was pH dependent and apparently related to an ionic interaction with the ionized carboxylate groups in the polymer. The pH dependency of the calcium binding was more closely related to the intrinsic pKa (4.3) of the acrylic acid residues in the polymer rather than the apparent pKa (6.8) of the polymeric species.

Kinetics of emulsion copolymerization with acrylic acids

Abstract: A kinetic model is presented that describes the reaction behavior of emulsion copolymerization systems where significant polymerization occurs in both the particle and aqueous phases. Equations for predicting aqueous-phase free-radical concentrations and aqueous-phase and particle-phase reaction rates are developed. A method for estimating the radical entry rate coefficient is also presented. The model is applied to two seeded carboxylated emulsion copolymerization systems, acrylic acid-styrene and methacrylic acid-styrene. Both experimental and predicted results reveal that the reaction behavior is greatly affected by the type of acid monomer, partition of monomer between the various phases, and locus of polymerization. The mechanism for the acrylic acid-styrene system is more complicated than that for the methacrylic acid-styrene system. Evidence suggests that the primary reaction locus in the acrylic acid-styrene system shifts from the particles to the aqueous phase after the hydrophobic monomer, styrene, has been consumed.

Aqueous resin composition

Abstract: PURPOSE:To prepare an aq. resin compsn. having an excellent low-temp. storage stability and giving a film excellent in the oil resistance, water resistance, and smoothness by compounding a specific aq. polymer with a hydrazine compd. having at least two hydrazino groups. CONSTITUTION:A monomer component comprising 2-50 pts.wt. unsatd. carboxylic acid (e.g. acrylic acid), 1-30 pts.wt. unsatd. compd. contg. at least one carbonyl group selected from the group consisting of a ketone group and an aldehyde group (e.g. diacetone acrylamide), and 20-97 pts.wt. monomer copolymerizable with these monomers (e.g. butyl acrylate) is soln.-polymerized in a polar solvent (e.g. ethylene glycol monomethyl ether) in the presence of an oil-sol. polymn. initiator (e.g. benzoyl peroxide) to give a copolymer, which is then neutralized and made aqueous with an aq. alkali soln. (e.g. aq. ammonia) to produce an aq. polymer. The resulting polymer is compounded with a hydrazine compd. having at least two hydrazino groups (e.g. adipic acid dihydrazide).

Use of an aqueous swollen macromolecule-containing system as water for fire fighting

Abstract: In the fighting of fires or protection of objects from fire by applying thereto water, the improvement which comprises dispersing in the water particles of a cross-linked water-insoluble but hightly water-swellable acrylic acid derivative polymer in an amount insufficient to bring the viscosity above 100 mPa's. Advantageously, the particles are present in an amount such that after swelling the swollen particles hold 60 to 70% by weight of the total water, the particles are from 0.1 to 3 mm in diameter and are present in from 0.1 to 0.6% by weight of the water, the polymer being a copolymer of an acrylic acid, the water containing silicic acid and/or a silicate as well as sodium, potassium or ammonium ions. The water is freely pumpable but the swollen particles adhere to surfaces they contact rather than running off rapidly.

Asymmetric Diels–Alder Reactions of an Acrylic Acid Derivative Using a Chiral Titanium Catalyst

Abstract: Asymmetric Diels–Alder reactions of an acrylic acid derivative using a catalytic amount of a chiral titanium reagent were performed with several dienes. The titanium catalyst was prepared by the al...

Process for oxidation of propane

Abstract: Disclosed is a process for the partial oxidation of propane to yield acrylic acid, propylene, acrolein and acetic acid by contacting propane in admixture with a molecular oxygen-containing gas in a reaction zone with an oxidic solid catalyst that 1) contains the components and proportions represented by the empirical formula Bi.sub.b Mo.sub.c V.sub.v A.sub.a D.sub.d E.sub.e O.sub.x wherein A is one or more of K, Na, Li, Cs and Tl, D is one or more of Fe, Ni, Co, Zn, Ce and La, E is one or more of W, Nb, Sb, Sn, P, Cu, Pb, B, Mg, Ca and Sr, a, d and e are each zero-10 b is 0.1-10 c is 0.1-20 v is 0.1-10 c:b is from 2:1 to 30:1 v:b is from 1.5:1 to 8:1 and 2) is made by performing a bismuth molybdate containing composition having at least 0.67 atoms of Mo per atom of Bi, before combining with any vanadium compound.

Slump retaining agent

Abstract: A polymeric composition which reduces the loss of flowability of a cementitious composition comprises at least one polymer as a salt thereof having the form of a copolymer of (a) a maleic anhydride half-ester with a compound of the formula I RO(AO).sub.m H (I) where R is a C 1-20 alkyl group, A is a C 2-4 alkylene group and m is an integer from 2-16; and (b) a monomer having the formula II CH.sub.2 ═CHCH.sub.2 -(OA).sub.n OR (II) where n is an integer from 1-90. In a preferred embodiment, there is present a polycarboxylate salt which is at least one polymer or copolymer comprising at least one of the monomers acrylic acid, methacrylic acid, maleic anhydride, maleic acid and maleic acid monoester, polymer and polycarboxylate salt being blended in the proportion of 0.1-10 parts of weight of polymer per part of polycarboxylate salt. Cementitious compositions such as concrete in which such polymeric compositions are included maintain their slump properties.

pH-responsive swelling of the ultrafine microsphere

Abstract: The pH dependent swelling of methyl methacrylate/acrylic acid copolymer microspheres having a diameter of tens of nanometers is described. The swelling mirrors that of bulk gels with the exception that a loss steep slope in pH swelling was observed in the case of microspheres

Process for producing improved superabsorbent polymer aggregates from fines

Abstract: Improved water absorbent polymers can be prepared by agglomerating acrylic acid gel polymer fines with small quantities of difunctional epoxides.

Residual reactivity for surface grafting of acrylic acid on argon glow-discharged poly(ethylene terephthalate) (PET) films

Abstract: The wettability of poly(ethylene terephthalate) (PET) films in water was significantly improved upon exposure to argon glow discharge. Depending upon the lengths of glow-discharge exposure, the water contact angle (CA) of the untreated film (73.1° ± 0.1°) was reduced to between 33.7° and 41.0° on the argon glow-discharged films. Wettability decay was observed during the initial few days. Depending upon the treatment time, the water CA stabilized 4–7 days after the treatment and the extent of the wettability decay ranged from 4.3° to 7.6°. The residual reactivity of the glow-discharged surfaces was captured by exposing the glow-discharged PET to acrylic acid in the liquid and vapor phases. Optimal water CAs of 54.0° and 41.9° were achieved in the liquid-phase and the vapor-phase exposures, respectively. Wettability decay of these acrylic acid-grafted PET surfaces was very small (0°–1.9°) for the liquid-phase reactions and negligible (0.3°–0.6°) for the vapor-phase reactions. The near absence of wettability decay or the greater stability of the grafted surfaces suggested the almost complete dissipation of the residual reactivity through reactions with acrylic acid. Surface morphology of the untreated as well as the acrylic acid-grafted PET surfaces were examined and detailed by scanning electron microscopy.

Biodegradable, liquid impervious films

Abstract: Liquid impervious, biodegradable films are disclosed. In particular, the films comprise a blend of an interpenetrated network of destructurized starch with ethylene/acrylic acid copolymers or ethylene/vinyl alcohol copolymers, and an aliphatic polyester such as polycaprolactone. Diapers, sanitary napkins, pantiliners, and the like, containing backsheets prepared from the foregoing materials are also disclosed.