THE DYNAMIC-MECHANICAL ANALYSIS OF HYDROGEL ELASTOMERS

An internal liquid bath which can be fitted into the furnace of a Perk in-Elmer DMA-7 has been developed. This new internal liquid bath allow s the samples to be tested by dynamic mechanical analysis (DMA) in a l iquid medium, not only under isothermal condition but also in the temp erature scan mode. It overcomes problems such as sample dehydration wh en using DMA for hydrogel materials and soft tissues and is superior t o the external liquid bath which is normally difficult to run in the t emperature scan mode. A plot of program temperature versus sensor temp erature, demonstrates that introducing the extra mass of the liquid ba th and the liquid medium does not interfere the system when operating in the temperature scan mode. DMA equipped with this new liquid bath h as been used in studying poly(vinyl alcohol) (PVA) hydrogel samples; t he results are discussed.