RECOVERABLE WORK VERSUS ASYMPTOTIC RELAXATION MODULUS IN AGAR, CARRAGEENAN AND GELLAN GELS

Cylindrical specimens of agar, carrageenan and gellan gels (1&2%) were uniaxially compressed to various predetermined strain levels and then decompressed. In an independent set of tests, specimens of the same gels were compressed to the same strains and then allowed to relax. Both the percent recoverable work, calculated from the stress-strain relationships in the compression-decompression cycles and the magnitude of the asymptotic relaxation modulus, calculated from the normalized and linearized relaxation curves, decreased as the strain increased. In all three gels there was a linear correlation between the percent recoverable work and the magnitude of the asymptotic modulus at corresponding strains, a sign that both parameters are indicative of these gels' degree of elasticity and the latter's strain dependency.