Published July 1960
| Version v1
Book
Cross-Linking of P.V.A. by Gamma Radiation
Creators
Description
The action of gamma rays on aqueous solutions of polyvinyl alcohol was observed by determination of the viscosity, sedimentation constant and acetylation rate. There was a very definite critical concentration, 0.28%, below which a B gel could not be formed by any dose. Above the critical concentration, the chief reaction was apparently intermolecular cross-linking which increased with dosage. Below the critical concentration the reactions were much more complex. At small doses there was probably some competition between inter- and intra- molecular cross-linking and the formation of more symmetrical molecular clusters. At higher doses the aggregates and the molecular clusters were subject to more and more internal and external cross-linking, leading finally to the formation of micro-gel particles. At decreasing concentrations (0.2 - 0.6%) intra-molecular cross-linking apparently became increasingly important. The effects of radiation were thought to depend upon the initial concentration of the polyvinyl alcohol solutions. (author)
Abstract (French)
L'action des rayons gamma sur des solutions aqueuses d'alcool polyvinylique a ete suivie par determination de la viscosite, de la constante de sedimentation et du taux d'acetylation. Il existe une concentration critique bien definie 0,28%, au-dessous de laquelle il est impossible d'obtenir la formation d'un gel B quelque soit la dose. Au-dessus, le phenomene important semble etre une reticulation intermoleculair e qui augmente avec la dose. Au-dessous de la concentration critique, les phenomenes sont beaucoup plus complexes. Aux faibles doses il y a probablement competition entre les phenomenes de pontage inter- et intramoleculaires et formation d'amas moleculaires de configuration plus symetrique. A doses plus fortes, les aggregats et les amas moleculaires subissent un pontage interne et externe de plus en plus prononce avec finalement formation de particules de micro-gel. A des concentrations de plus en plus faibles (0,2-0,06%) il semble que le phenomene de reticulation intramoleculaire devienne de plus en plus important. En conclusion, les effets des rayonnements sur les solutions d'alcool polyvinylique seraient fonction de la concentration initiale de ces solutions. (author)Abstract (Spanish)
Los autores estudiaron la accion de los rayos gamma sobre soluciones acuosas de alcohol polivinilico, determinando la viscosidad, constante de sedimentacion y grado de acetilacion del polimero. Existe una concentracion critica bien definida, a saber, 0,28 por ciento, por debajo de la cual es imposible obtener el gel B, sea cual fuere la dosis administrada. Por encima de esa concentracion, el fenomeno mas importante consiste al parecer en una reticulacion intermolecular cuyo grado aumenta en funcion de la dosis. Por debajo de la concentracion critica, los fenomenos son mucho mas complejos. Cuando las dosis son pequenas, es probable que los fenomenos de reticulacion inter e intramolecular compitan con la formacion de conglomerados moleculares de configuracion mas simetrica. A dosis mas elevadas, los agregados y los conglomerados moleculares experimentan una reticulacion interna y externa cada vez mas pronunciada, que conduce finalmente a la formacion de particulas de microgel. A medida que la concentracion disminuye (de 0,2 a 0,06 por ciento), el fenomeno de reticulacion intramolecular adquiere importancia creciente. En conclusion, puede admitirse que los efectos ejercidos por las radiaciones sobre las soluciones de alcohol polivinilico dependeran de la concentracion inicial de esas soluciones. (author)Abstract (Russian)
Dejstvie gamma-luchej na vodnye rastvory polivinilovogo spirta soprovozhdalos' ustanovleniem vyazkosti, postoyannogo osazhdeniya i stepeni atsitilirovaiiya. Sushchestvuet tochno ustanovlennaya kriticheskaya kontsentratsiya v 0,28%, nizhe kotoroj nevozmozhno poluchit' obrazovanie massy V, kakova by ni byla doza. Esli kriticheskaya kontsentratsiya budet prevyshat' 0,28, to nablyudaetsya mezhmolekulyarnaya poperechnaya svyaz, kotoraya vozrastaet s uvelicheniem dozy. Nizhe kriticheskoj kontsentratsii yavleniya yavlyayutsya bolee slozhnymi. Pri slabykh dozakh proiskhodit, vidimo, sopernichestvo mezhdu yavleniyami mezh- i vnutrimolekulyarnoj poperechnoj svyazi s obrazovaniem simmetrichno raspolozhennykh molekulyarnykh grupp. Pri bolee sil'nykh dozakh agregaty i molekulyarnye gruppy ispytyvayut vse bolee yasno vyrazhennuyu vnutri- i meyashoperechnuyu svyaz', i v konechnom schete obrazuyutsya mikro-gelievye chastitsy. Pri postepenno oslabevayushchej kontsentratsii (0,2-0,06%) obnaruzhivaetsya, chto yavlenie vnutrimolekulyarnogo poperechnogo secheniya stanovitsya vse bolee i bolee znachitel'nym . V zaklyuchenie, dejstviya oblucheniya na rastvory polivinilovogo spirta zavisyat ot pervonachal'noj kontsentratsii ego rastvorov. (author)Additional details
Additional titles
- Original title (English)
- Reticulation de l'alcool polyvinylique par les rayons gamma; Dejstvie gamma-luchej na poperechnuyu svyaz' polivinologo spirta; Reticulacion del alcohol polivinilico por irradiacion gamma
Publishing Information
- Publisher
- IAEA
- Imprint Place
- Vienna (International Atomic Energy Agency (IAEA))
- Imprint Title
- Large radiation sources in industry. Proceedings of a conference on the application of large radiation sources in industry. V. I
- Imprint Pagination
- 492 p.
- Series
- Proceedings Series
- Journal Page Range
- p. 341-346
- ISSN
- 0074-1884
Conference
- Title
- Conference on the application of large radiation sources in industry
- Dates
- 8-12 Sep 1959
- Place
- Warsaw (Poland)
INIS
- Country of Publication
- International Atomic Energy Agency (IAEA)
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 43113111
- Subject category
- S38: RADIATION CHEMISTRY, RADIOCHEMISTRY AND NUCLEAR CHEMISTRY;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- ACETYLATION; AQUEOUS SOLUTIONS; COMPETITION; COMPLEXES; CROSS-LINKING; DOSES; GAMMA RADIATION; GELS; MOLECULAR CLUSTERS; PARTICLES; PVA; SEDIMENTATION; VISCOSITY
- Descriptors DEC
- ACYLATION; ALCOHOLS; CHEMICAL REACTIONS; COLLOIDS; DISPERSIONS; ELECTROMAGNETIC RADIATION; HOMOGENEOUS MIXTURES; HYDROXY COMPOUNDS; IONIZING RADIATIONS; MIXTURES; ORGANIC COMPOUNDS; ORGANIC POLYMERS; POLYMERIZATION; POLYMERS; POLYVINYLS; RADIATIONS; SOLUTIONS
Optional Information
- Notes
- 2 figs., tab.
- Secondary number(s)
- STI/PUB--12(Vol.1)