NEW METHOD FOR MEASURING POISSON RATIO IN POLYMER GELS

A new method for measuring the Poisson's ratio of polymer gels has bee n proposed and has been experimentally demonstrated. The method is bas ed on different swelling behaviors of free and constrained gels. The P oisson's ratio of polyacrylamide gel, as a function of crosslinker con centration, has been measured using this method and has been found to be sensitive to the amount of polymerization initiator. The results ar e compared with results determined by other methods. (C) 1993 John Wil ey & Sons, Inc.