| Numéro |
J. Phys. II France
Volume 2, Numéro 9, September 1992
|
|
|---|---|---|
| Page(s) | 1745 - 1754 | |
| DOI | https://doi.org/10.1051/jp2:1992231 | |
J. Phys. II France 2 (1992) 1745-1754
Swelling and rheological properties of poly methyl methacrylate thermoreversible gels
Zarmina Fazel1, Nazir Fazel1, 2 and Jean-Michel Guenet11 Laboratoire d'Ultrasons et de Dynamique des Fluides Complexes, Universtié Louis Pasteur, CNRS URA 851, 4 rue Blaise Pascal, F-67070 Strasbourg Cedex, France
2 Laboratoire de Physique des Liquides et Interfaces, Université de Metz, 57070 Metz Cedex, France
(Received 17 March 1992, accepted in final form 9 June 1992)
Abstract
The stress relaxation as well as the variation of the isochrone compression modulus as a function of concentration have been
studied with PMMA thermoreversible gels. Two solvents have been used : bromobenzene and ortho-xylene. The swelling behaviour has also bee examined. Only gels in bromobenzen swell significantly. The swelling ration
vs. polymer concentration has been interpreted by means of a theory derived for two-phase systems. In both solvents considerable
stress relaxation is observed. In the early stage this relaxation obeys a power law
with
to 0.13 in bromobenzene and 0.23 in ortho-xylene. For this reason isochronal moduli at 120 s have been considered. Modulus-concentration relations are as follows :
for non-swollen gels in bromobenzene,
for gels swollen to equilibrium in bromobenzene,
in ortho-xylene. These results are discussed by means of theories developed for rigid gels in the light of the molecular structure
determined by small-angle neutron scattering (preceding paper published in the issue of August).
46.30J - 81.20S - 82.70
© Les Editions de Physique 1992