Greffage radiochimique de l'acide methacrylique sur des films de polytetrafluoroethylene

✍ Scribed by H. Ali-Miraftab; A. Chapiro; T. Le Doan

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 569 KB
• Volume: 14
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(78)90004-6

✦ Synopsis

R£'sum6--On a greff6 de l'acide m6thacrylique dans la masse de films de PTFE de 50 tzm d'6paisseur en h-radiant ces films darts des solutions aqueuses de monom6re renfermant du CuC12. On a 6tudi6 l'influence de l'intensit6 du rayonnement et de la temp6rature sur la ri~action. Le gonflement des films greff6s a 6t6 examin6 dans les solvants des greffons suivants: eau, m6thanol, DMF ainsi que dans des m61anges de ces solvants. On a d6termin6 darts chaque cas les rapports molaires correspondant au gonflement limite. On a trouv6 par ailleurs que les films greff6s gonflent dans les acides carboxyliques: acides m6thacrylique, acrylique et ac6tique qui ne sont pas solvants des greffons. Ce gonflement qui est beaucoup plus lent que le gonflement dans les boris solvants, serait df~ hune association des groupes carboxyles du solvant avec ceux du polym~re.

Abstraet--Methacrylic acid was grafted into the bulk of PTFE films 50 tzm thick by irradiating the films in aqueous solutions of monomer containing CuCI2. The influences of radiation dose-rate and of temperature were investigated. The swelling of the grafted films was studied in the following solvents for the grafted branches: water, methanol, DMF and their mixtures. In each case the molar ratios corresponding to the limiting swelling were determined. It was further found that the grafted films swell in carboxylic acids such as methacrylic, acrylic and acetic acids, which are non-solvents for the grafted branches. This swelling is much slower than the swelling in good solvents. It is suggested that it results from a molecular association of the carboxyl groups of the solvent with those of the polymer.