Elasticity Study of PAAm-κ C Composite Prepared in Various κ C Content and Measured at Several Temperatures

Abstract

Polyacrylamide (PAAm)-kappa carrageenan (κC) composite gels were prepared via free radical crosslinking copolymerization with various (w/v) percentages of κC in the range between 0.5 and 3 (w/v)% of κC. Elasticity properties such as stress, strain and compressive elastic modulus, S of these composite gels were studied in various κC content and at several temperatures. The content and temperature dependence of the compressive elastic modulus, S of the swollen PAAm-κC composite gels due to volume phase transition were produced by using tensile testing technique. It is understood that the compressive elastic modulus was found to decrease up to 1 (w/v)% of κC, and then increase by increasing κC contents, at constant temperatures. The composite preserves the ability to undergo the volume phase transition and its compressive elastic modulus is found to be strongly dependent on the κC content and temperature. It is observed that the compressive elastic modulus increased when temperature is increased up to 40• C and then decreases below this temperature for all composite gels. However, PAAm-κC composite gel presented lower values for the compressive elastic modulus, showing a minima at 40• C for 1 (w/v)% of κC content gel.