Search results for "acrylic acid"

1995

45 g of poly(acrylic acid) (PAA 500) with a trimodal molar mass distribution (Mw = 500 kg/mol, (Mw/Mn) −1 = 2.33) were fractionated by means of CPF (continuous polymer fractionation) in two steps using 1,4-dioxane as solvent. The counter-current extraction was performed in a glass column (length: 190 cm, diameter: 1.5 cm) filled with a network of wires, introducing the feed 75 cm from its upper end. The distribution of the highest molar mass fraction (Mw = 760 kg/mol) is unimodal and comparatively narrow ((Mw/Mn) −1 = 0.66). Indications exits that fractionation is not only taking place with respect to molar mass but also with respect to tacticity. Mit Hilfe der kontinuierlichen Polymerfrakt…

Polymere 3-acryloyloxyalkyl- und 3-acryloyloxyaryl-4-thiazolidone als strahlenschutzsubstanzen

1977

The syntheses of 3-acryloyloxyalkyl- and 3-acryloyloxyaryl-2-phenyl-4-thiazolidones (3a–c) from the corresponding hydroxyl derivatives 2a–c and acrylic acid chloride are described. These monomers were homopolymerized and copolymerized with N-vinyl-2-pyrrolidone by radical initiation. The resulting water soluble copolymers were tested in animals for radioprotective activity and prolongation of efficiency.

Über die herstellung molekulareinheitlicher cyclooligomerer und ihre spaltung. III. Mitt.: Modelle für matrizenreaktionen

1967

Zunachst werden Faktoren genannt, die eine synthetische Matrizenreaktion beeinflussen konnen. Dann wird die Herstellung von Estern aus Acrylsaurechlorid mit Phenolaten molekulareinheitlicher, phenolischer Mehrkernverbindungen (durch rationale Synthese1 hergestellte Novolake) beschrieben. Es fanden sich Bedingungen, unter denen eine Polymerisation der Acrylsaurereste auf ein und dasselbe Molekul beschrankt blieb. Diese neue Polymerisationsvariante wird intramolekulare Cyclooligomerisation genannt, da die erhaltenen Produkte molekulareinheitliche Cyclooligomere sind. Eine Hydrolyse dieser Cyclooligomeren ergab molekulareinheitliche Sauren, wie die Umsetzung mit p-Nitrobenzylbromid sowie Eleme…

Gemischte Diester von 2,2′-Methylendiphenolen mit Methacryl- und Crotonsäure und ihre Polymeren. 13C NMR-Untersuchungen zur Strukturaufklärung

1984

The structure of mixed diesters of three 2,2′-methylenediphenols with crotonic acid and methacrylic acid was studied by 13C NMR-spectroscopy. The position of the two acyl groups, expected from the synthetic pathway, was unambiguously confirmed by comparison with the corresponding mono- and diesters containing the same acyl group. In the same way, it was shown that the crotonoyl residue is not involved in the radical polymerisation of these esters.

A New Versatile Synthesis of N,N′,N″,N″′-Tetra-(2-carboxyethyl)-and N,N′,N″,N″′-Tetra-(3-aminopropyl)-tetraazacycloalkanes by Michael Addition of Pol…

1996

Abstract A smooth and convenient one step synthesis of N,N′,N″,N″′-tetra-(2-carboxyethyl)-tetraazacycloalkanes is reported. These compounds are synthesized by Michael addition of tetraazacycloalkanes to acrylic acid. The same Michael addition of tetraazacycloalkanes to an excess of acrylonitrile also leads to the corresponding tetracyanoethylated derivatives. The reduction of such tetracyanoethylated compounds is a new way of preparation for the corresponding primary amines.

Herstellung und eigenschaften von photometrisch quantitativ bestimmbaren, bei der polymerisation vernetzenden bisacrylsäureestern und von bispropions…

1969

Es wurden 6 Bisacrylsaureester hergestellt, die photometrisch quantitativ bestimmbare Strukturgruppen enthalten. Angaben zur Loslichkeit, IR-, UV-Absorptions- und 1H-NMR-Spektren dienten zur Charakterisierung der Verbindungen. Daneben wurden Dipropionsaureester synthetisiert, die sich durch Austausch der Acrylsaure- gegen die Propionsaurereste von den Bisacrylsaureestern ableiten. Verdunnte Losungen der Bisacrylsaure- und Dipropionsaureester folgen im Bereich von 250–450 mμ dem BOUGUER-LAMBERT-BEER-schen Gestz. Aus den Ergebnissen der Homopolymerisation der Bisacrylsaureester last sich schliesen, welche Ester fur eine einfache photometrische Analyse schwach vernetzter Copolymerer in Betrach…

ChemInform Abstract: A New Versatile Synthesis of N,N′,N′′,N′′′-Tetra(2-carboxyethyl)- and N,N′,N′′,N′′′-Tetra(3-aminopropyl)-tetraazacycloalkanes by…

2010

Abstract A smooth and convenient one step synthesis of N,N′,N″,N″′-tetra-(2-carboxyethyl)-tetraazacycloalkanes is reported. These compounds are synthesized by Michael addition of tetraazacycloalkanes to acrylic acid. The same Michael addition of tetraazacycloalkanes to an excess of acrylonitrile also leads to the corresponding tetracyanoethylated derivatives. The reduction of such tetracyanoethylated compounds is a new way of preparation for the corresponding primary amines.

Copolymerization of Vinylidene Fluoride and Acrylic Acid in Supercritical Carbon Dioxide

2010

The free-radical copolymerization of vinylidene fluoride (VDF) and acrylic acid (AA) was carried out in supercritical carbon dioxide using both precipitation and dispersion techniques in the presence of an ammonium carboxylate perfluoropolyether compound. Formation of a copolymer was confirmed by variable contact time CP MAS NMR spectroscopy. Macromolecular matrices were significantly enriched in AA with respect to the initial feed composition and we found that the nonfluorinated monomer has a much higher reactivity ratio with respect to VDF. The cumulative concentration, crystallinity, and water affinity of the synthesized copolymers could be modified changing the initial feed composition,…

Control of Corona Composition and Morphology in Aggregates of Mixtures of PS-b-PAA and PS-b-P4VP Diblock Copolymers: Effects of pH and Block Length

2014

The corona compositions and morphologies in aggregates of mixtures of amphiphilic polystyrene-block-poly(acrylic acid) (PS-b-PAA) and polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) diblock copolymers are influenced by controllable assembly parameters such as the hydrophilic block length and solution pH. The morphologies and corona compositions of the aggregates were investigated by transmission electron microscopy and electrophoretic mobility, respectively. When mineral acids or bases are present during aggregate formation, they can exert a strong influence on the corona composition. Morphology changes were also seen with changing pH, as well as changes in corona composition, specifica…

Oligonucleotides-decorated-poly(N-vinyl pyrrolidone) nanogels for gene delivery

2013

Pulsed electron-beam irradiation of a semi-dilute poly(N-vinyl pyrrolidone) (PVP) aqueous solution in the presence of acrylic acid has led to a carboxyl functionalized nanogel system. Nanoparticles hydrodynamic size and surface charge density, in water and as a function of pH, were investigated by dynamic light scattering and laser doppler velocimetry, respectively. Nanogels (NGs) were proved not to be cytotoxic at the cellular level. Indeed, they rapidly bypass the cellular membrane to accumulate in specific cell portions of the cytoplasm, in the perinuclear area. The availability of pendant carboxyl groups on the crosslinked PVP NGs core prompted us to attempt their decoration with a sing…