Polymeric Carboxylic Acid Research Articles

The hydration of a glass‐ionomer (ASPA) cement

AbstractThe hydration of chemical species formed in the cement‐forming reaction has been studied by measuring the evaporable, and non‐evaporable water contents of a glassionomer cement at various stages in its history. Hydration is accompanied by increase in strength and, as loose water is removed from the matrix, a decrease in plasticity. Hydration is attributed to ionisation of the polymeric carboxylic acid and transfer of metal ions from the glass to the polyelectrolyte.

ChemInform Abstract: ANIONIC POLYMERS AND BIOLOGICAL ACTIVITIES. EFFECTS OF SOME NEW POLYCARBOXYLIC ACIDS ON THE ASCITIC SARCOMA 180 OF MICE

AbstractPolymere Carbonsäuren auf Basis von nach üblichen Verfahren hergestellten Copolymeren der Acrylsäure (I)‐(III) werden als anionische Polymere hinsichtlich einer tumorhemmenden Wirkung untersucht.

Anionic polymers and biological activities. Effects of some new polycarboxylic acids on the ascitic sarcoma 180 in mice.

Eleven new polymeric carboxylic acids with widely different solubilities in water have been synthesized. The activities of these polymers against the ascitic sarcoma 180 tumor of mice and their acute toxicities in mice have been compared with molecular parameters of the polymers such as molecular weights, charge densities, and abilities to complex calcium and magnesium ions. The maximum effectiveness of these polymers against ascitic sarcoma 180 of mice is greatest for those polymers having fewer carboxyl groups ionized at pH 7. Toxicities are lower for polymers having more carboxyl groups ionized at pH 7.

Hydrogen bonding and structure formation of molecules of unsaturated carboxylic acid polymers in organic solvents

IR spectroscopy has been used to investigate the processes involved in the formation of hydrogen bonds in solutions of unsaturated carboxylic acid polymers in dioxane and in mixtures of dioxane with small additions of methanol. It has been shown that the poly-acid macromolecules have a secondary structure formed by intra-chain hydrogen bonds (COOH-dimers) between monomer links that are both remote and also neighbouring in the chain. The degree of intra-chain ordering is determined by the chemical structure of the polyacid. Structure formation of the solutions has been studied close to the phase separation temperature.

Esterification of polymeric carboxylic acids

AbstractPolymers containing pendant carboxyl groups have been essentially completely esterified with little apparent change in molecular weight by the use of one of the following reagents: (1) trialkyl orthoesters, (2) dimethylformamide dialkyl acetals, (3) tertiary amines followed by alkyl halides, (4) quaternary ammonium hydroxide followed by alkyl halides. The use of some of these methods permits preparation of certain polymers that were previously not readily accessible.

Additives for alkaline scale control at temperatures above 93°C (200°F)

Laboratory tests have been used to screen chemical additives suitable for alkaline scale control at temperatures between 93°C and 121°C (200–250°C). The tests have shown that the quantity of solids deposited and the heat transfer performance depend to some extent upon the physical nature of the deposit and that this depends in turn upon the type of chemical used. Low molecular weight polyelectrolytes have been found the most suitable additives and a polymeric carboxylic acid has been found particularly effective. The chemical is being field tested and initial results indicate a 36-day operating period between acid cleans.

DESALINATION ECONOMICS IMPROVE WITH DISCOVERY OF SCALE CONTROL ADDITIVE

New technology developed by CIBA‐GEIGY (UK), in collaboration with the United Kingdom Atomic Energy Authority, looks like providing a breakthrough in the control of scale in high temperature desalination plant. CIBA‐GEIGY are claiming that the product, based on a polymeric carboxylic acid, is effective with brine temperatures up to 250°F, has minimal handling, storage and corrosion problems and will reduce operating and capital costs on new high temperature plants. The company has designated the product Belgard EV and it is an extension of the recently introduced Belgard 800 range of water treatment chemicals.

Photosensitive Ionomer. II. Preparation of Mercurous Copoly(vinyl alcohol–acrylate) and Properties of the Plate

The disproportionating reaction of mercurous acetate was used in conjunction with polymeric carboxylic acid in order to produce a new type of photosensitive system. As for the polymeric acid, various copolymers of vinyl alcohol and acrylic acid were prepared by radical copolymerization of vinyl acetate and acrylic acid with varying monomer ratios and volumes of xylene used as a solvent. The polymeric acid was neutralized with sodium hydroxide and then converted to a mercurous salt. Photosensitive plates were prepared by coating glass plates with a dispersion of mercurous copoly(vinyl alcohol–acrylate).It was found that the plates were sensitive to ultraviolet light, and that a dark brown image was formed by a printing-out process. The latent image was proved to be developed by hydroquinone. Photographic image formation was due to metallic mercury which was isolated as a product of the disproportionating reaction. When immersed in an acetic acid solution, the photosensitive layer of the unexposed part swelled and became detached from the plate, but the layer of the exposed part was unchanged, and a relief image was fixed on the plate. The image formation was ascribed to ionic crosslinking by mercuric ions formed in the disproportionating reaction of mercurous ion.

各種の高分子カルボン酸の酸無水物形成

各種の高分子カルボン酸の酸無水物形成

On the Ionisation of Some Polymeric Carboxylic Acids

On the Ionisation of Some Polymeric Carboxylic Acids