APPLICATION OF NETWORK MODELS TO PHYSICAL GELS

There are a number of physical models which describe properties of phy sical gels, such as the time dependence of viscoelastic properties, st ress-strain dependence, and the concentration dependence of gelation) time and of gel modulus. One of the latter, due to ourselves, has been useful for fitting data for a number of systems including WC and gela tin gels. However one of its limitations is that it has three ''molecu lar'' parameters, and only infrequently can these be estimated from in dependent experiment. In some cases a better way of testing the model' s viability is to compare data concurrently for different concentratio ns and molecular weights in a surface fit. This paper reviews earlier work and illustrates the extended technique applied to new data for ag arose and PVA gels.