Water absorption and desorption by a superabsorbent polymer - Drying a swollen polymer by conventional heating and in a microwave field

The study of the kinetic dryness of a swollen polymer has shown that the re actions performed under pressure of water vapour are generally more quick t han those realised under controlled air and pressure. The nature of the gas sing the atmosphere modifies the influence of parameters (temperature and p ressure) on the kinetic reaction. The use of higher masses permits a comple te modification of the kinetic regime which limits the dryness reaction: it moves from a phenomena controlled by the evaporation followed by a tridime ntional diffusion of the small masses, to a phenomena governed by a tridime ntional diffusion of the high masses heated conventionally. To examine l'ef fect of microwave field, we have dry a swollen polymer under a microwave fi eld. The analysis of the results shows that the held interacts with the pol ymer, which provokes its degradation in the case where the employed forces are crucial (up to 100 W). (C) 2000 Elsevier Science B.V. All rights reserv ed.