Creep and solvent squeeze behavior of κ-carrageenan gels under compression

Creep by solvent squeeze of cylindrical κ-carrageenan gels is investigated. A phenomenological model to describe the creep and the solvent squeeze of polymer gels is also presented. Under compression, the creep of gels proceeds at a constant diameter except for the initial stage of creep. The change in height of the gels is well reproduced by the sum of three exponential terms, each of which is specified by the combination of displacement and retardation time. The displacement for the second mode, which corresponds to the second longest retardation time, becomes largest for all gel specimens. Three retardation times are commonly proportional to the square of initial diameter of gel specimens. Based on the proposed model, the spring constant in the second mode becomes smallest and the permeability corresponding to the third mode becomes larger than those in the other two modes.