COMPARISON BETWEEN THE ELASTICITY OF POLYACRYLAMIDE AND POLYACRYLIC GELS

We measured the Young modulus E of polyacrylamide and polyacrylic gels as a function of the crosslink and polymer concentrations. We found t hat the variation of E with these two parameters is completely differe nt for the two kinds of gels. For the polyacrylic gels, E is an increa sing function of the crosslink and polymer concentrations. However, in the case of the polyacrylamide gels, E increases with polymer concent ration but not always with the crosslink concentration, For low polyme r concentrations, E may saturate or exhibit a maximum when increasing the crosslink concentration. We proposed qualitative interpretations t o explain this different behavior.