Showing papers on "Acrylic acid published in 1990"

Fourier transform infrared spectroscopic studies of the reactivity of vanadia-titania catalysts toward olefins. 1. Propylene

Abstract: The adsorption and transformation of propylene and of several O-containing C{sub 3} organic molecules (namely isopropyl alcohol, acetone, allyl alcohol, acrolein, and acrylic acid) on vanadia-titania in the temperature range 150-673 K have been investigated by IR spectroscopy. At low temperatures (150-200 K), propylene adsorbs as such through {pi}-bonding and reacts later to give an adsorbed species identified tentatively as an allyl radical. Alternatively, it undergoes addition by a surface OH group to given an isopropoxy species. At least two main surface pathways for propylene transformation are active, leading to surface species functionalized at C{sub 2} (isopropoxy species and acetone) and at C{sub 1} (acrolein and acrylates) as well as products arising from coupling of the allyl radical. The results are discussed in relation to literature data concerning the heterogeneously catalyzed selective oxidation of propylene carried out on vanadia-titania as well as on bismuth-molybdate-based catalysts.

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.

Structure and surface properties of plasma polymerized acrylic acid layers

Abstract: Thin plasma polymerized layers of acrylic acid (PPAA) were deposited onto polyethylene and muscovite mica surfaces. Structure and surface properties of the deposited layer depend on the polymerization conditions. The content of carboxylic groups in the layer decreases, whereas the degree of crosslinking or branching increases, with increasing discharge power. A soft, sticky layer with a low contact angle against water is obtained when a low discharge power (5 W) is used. In contrast, a hard film with a rather high water contact angle is obtained when the discharge power is high (50 W). A surface force apparatus was employed to study some film properties including adhesion force, crack formation, and capillary condensation. The adhesion force between plasma polymerized acrylic acid layers prepared at a low discharge power is high in dry air. It decreases remarkably in humid air and no adhesion is observed in water. In dry air, the adhesion force between PPAA layers decreases as the discharge power increases.

Surface modification by continuous graft copolymerization. I. Photoinitiated graft copolymerization onto polyethylene tape film surface

Abstract: A process has been developed for continuous photoinitiated graft copolymerization of acrylamide (AM) and acrylic acid (AA) onto the surface of high-density polyethylene (HDPE) tape film, presoaked in a solution containing monomer and initiator under nitrogen atmosphere. As photoinitiator we have used benzophenone, which is efficient for photografting of polyolefins with acrylic monomers. The presoaking procedure of the tape film is very important for efficient photografting within short irradiation times. In ESCA spectra of the grafted tape film the relative intensity of the nitrogen over carbon peaks of film grafted with acrylamide is about 5–10% after 6 s irradiation time. The relative intensity of oxygen over carbon peaks in ESCA spectra of film grafted with acrylic acid is about 10–20% after 8 s irradiation time. The effects of varying the monomer concentration in presoaking solution and the different irradiation conditions on the grafting yield have been investigated. This technique has the advantages of being a continuous process with short irradiation times without requirements of vacuum conditions and appears to be promising for practical applications.

Separation of Organic Acid/Water Mixtures by Thin Porous Silica Membrane

Abstract: A method is proposed to prepare thin porous silica membrane which can be considered relatively stable against acids. The separation performance of this membrane for some organic acids (acetic acid, propionic acid, acrylic acid)/water mixtures has been studied experimentally by the pervaporation method and quite large fluxes of water and high separation factors have been achieved

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.

Complexation of poly(acrylic acid) and poly(methacrylic acid) with pyrene-end-labeled poly(ethylene glycol): pH and fluorescence measurements

Abstract: Etude de l'effet du pH sur le rapport des intensites d'emission de l'excimere du pyrene et du monomere. Les resultats montrent que l'interaction entre les groupes hydrophobes pyrene et les groupes hydrophobes α-methyl du PMAA ameliore la complexation. Un modele qualitatif resumant les interactions presentes dans les systemes PEG/PMAA et PEG/PAA et expliquant les donnees spectrales est propose

Grafting onto isotactic polypropylene. III, Gamma rays induced graft copolymerization of water soluble vinyl monomers

Abstract: Graft copolymerization of water soluble vinyl monomers such as acrylic acid and acrylamide onto isotactic polypropylene by the pre-irradiation method has been studied. Grafting was carried out in a water and water-methanol solvent system. The percentage of grafting has been determined as a function of (i), total dose (ii) concentration of monomers, (iii) reaction time, and (iv) the composition and amount of water-methanol solvent system. Water was found to be the best solvent for affording maximum grafting. The grafted samples were characterized by spectroscopic and thermogravimetric methods. Acrylic acid was found to be more reactive than acrylamide towards graft copolymerization.

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.

Chitosan-Poly(acrylic acid): Mechanism of Complex Formation and Potential Industrial Applications

Abstract: The food industry is interested in polyelectrolytic coagulants of natural origin for the clarification of food beverages and the recovery of colloidal and dispersed particles from processing waste streams. This paper discusses potential industrial applications of recent findings on polymer complex formation obtained with a chitosan-poly(acrylic acid) model system. Process recommendations could be made on the basis of the ionic strength, pH, and charged group concentration of the fluid to be treated. Ionic strength does not affect the complex formation process. The amount of chitosan in the complex formed is controlled by the solution pH. The mechanism of complex formation indicates that pH measurements could be used to monitor the coagulation process.

Surface modification by continuous graft copolymerization. III, photoinitiated graft copolymerization onto poly(ethylene terephthalate) fiber surface

Abstract: Photoinitiated grafting is an excellent method to modify the surface properties of a polymer. The presoaking photografting method applied to poly(ethylene terephthalate) (PET) with acrylic acid or acrylamide as monomer using benzophenone as photoinitiator has been investigated. The photografting proceeds under nitrogen atmosphere in a continuous process. The relative intensity of the ESCA lines of nitrogen over carbon of the fiber grafted with acrylamide increased from 3–4% (background) to 8% for 20-s irradiation time. Measured by titration, the amount of grafted poly(acrylic acid) is 0.821 and 1.528 mg/m2 with 0.5 M and 2.0 M acrylic acid concentration, respectively, in the presoaking solution at 10-s irradiation time. The dyeability of the fiber, measured by UV absorption, improved. The concentration of initiator and monomer and the solvent used affected the grafting yield. Appropriate conditions promoted photografting of the poly(ethylene terephthalate) fiber. Acetone was a somewhat better solvent than methylethylketone and methylpropylketone.

Method of treating water

Abstract: A method of treating and removing volatile organic contaminants from ground water by treating the water with effective amounts of a water-soluble polymeric sequesterant comprising polymers derived from acrylic acid or organic acid, followed by the addition of a biocide, eg, chlorine, and then subsequently passing the treated water through a packed column or air stripper wherein the volatile organic contaminants are removed by passing air in a counter-direction to the flow of water at temperatures ranging from about 40° to about 200° F

Hydrogels for site‐specific oral delivery. Poly[(acrylic acid)‐co‐(butyl acrylate)] crosslinked with 4,4′‐bis(methacryloylamino)azobenzene

Abstract: Copolymers of acrylic acid and butyl acrylate crosslinked with 4,4′-bis(methacryloylamino)-azobenzene were synthesized by radical copolymerization with different amounts of acrylic acid and crosslinker. They were characterized by equilibrium degree of swelling, modulus of elasticity in compression at pH 2 and 7, and effective network density. The acido-basic properties of crosslinked copolymers were compared with linear (soluble) ones of the same composition. The study of the dependence of the apparent dissociation constant (pKapp) on the degree of dissociation has shown that conformational transition from the compact to the random conformation of the polymeric chains occurs only in crosslinked copolymers. The high values of pKapp obtained indicate that strong Donnan effects and low polarity of environment of carboxy groups are operative in acido-basic equilibria.

Vinyl grafted lignite fluid loss additives

Abstract: A vinyl grafted lignite fluid loss additive comprising a lignite grafted with at least one vinyl monomer selected from the group consisting of: dimethylaminopropyl methacrylamide, methacrylamido propyltrimethyl ammonium chloride, N-vinylformamide, N-vinylacetamide, diallyl dimethyl ammonium chloride, diallylacetamide, and diallylamine. The vinyl monomer may also be blended with at least one co-monomer. Preferred co-monomers are: 2-acrylamido-2-methylpropanesulfonic acid, dimethylacrylamide, acrylamide, vinylpyrrolidone, vinylacetate, acrylonitrile, dimethylaminoethyl methacrylate, styrenesulfonate, vinylsulfonate, dimethylaminoethyl methacrylate methyl chloride quaternary, acrylic acid and its salts.

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.

Pd+2/Poly(acrylic acid) Thin Films as Catalysts for Electroless Copper Deposition: Mechanism of Catalyst Formation

Abstract: The mechanism involved in the initiation of electroless copper deposition onto dielectric substrates using Pd +2 /poly(acrylic acid) thin films is described

Internal resin-tackified acrylic polymers

Abstract: Acrylic copolymer PSA compositions having enhanced peel strength without substantially decreasing shear properties have been formulated by homogeneously incorporating the tackifying resin into the polymer matrix. The tackifying resin is dissolved into a solution of alkyl (meth) acrylate and (meth) acrylic acid monomers prior to polymerization. To enhance the molecular weight of the resultant PSA, the monomer/tackifier solution is emulsion polymerized in the absence of chain transfer agents, such as antioxidant additives typically found in commercially available tackifiers, and allylic hydrogen present in many unsuitable tackifiers.

Stain resistant treatment for polyamide fibers

Abstract: A stain resistant composition for fibers having polyamide linkages prepared by polymerizing an .alpha.-substituted acrylic acid or ester in the presence of a sulfonated aromatic formaldehyde condensation polymer, or by polymerization of a sulfonated hydroxyaromatic ester of an .alpha.-substituted acrylic acid or acrylic acid, and methods for making and applying the composition.

Ultrasonic calibration material and method

Abstract: Ultrasonic calibration material produced by polymerization of acrylamide with N,N'-methylene-bis-acrylamide in vacuum-degassed liquid solutions such as water, ethylene glycol, emulsions of non-miscible liquids with water and blends of liquids in which a homogeneous and permanent suspension of solid and liquid particles (e.g.: alumina, boron nitride, graphite, water-filled phenolic microspheres, glass microspheres, polyethylene, turpentine oil) is chemically achieved by polymerization of an acrylic acid polymer.

Method for production of acrylic acid

Abstract: OF THE DISCLOSURE A method for the production of acrylic acid by the vapor-phase oxidation of acrolein with a molecular oxygen-containing gas in the presence of a catalyst formed of an oxide or a composite oxide of a metal element composition represented by the following formula I: MoaVbWcWudXeYf (I) wherein X is at least one element selected from the group consisting of Zr, Ti and Ce, T is at least one element selected from the group consisting of Mg, Ca, Sr and Ba, and the subscripts a, b, c, d, e, and f are such that b = t to 14, 0

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.

Hydrophilic semipermeable membranes based on copolymers of acrylonitrile and hydroxyalkyl esters of (meth) acrylic acid

Abstract: Hydrophilic semipermeable membranes based on copolymers of acrylonitrile and hydroxy-C2-C4-alkyl esters of (meth) acrylic acid are provided The membranes have a substantial water regain at equilibrium, a wide range of ultrafiltration rates, and low solute adsorption by ion-exchange or hydrophobic interaction mechanisms The membranes are particularly suitable for processing protein containing fluids, especially biological fluids such as blood or plasmas

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.