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

Abstract

Polyacrylamide (PAAm)-kappa carrageenan (kappa C) composite gels were prepared via free radical crosslinking copolymerization with various (w/v) percentages of kappa C in the range between 0.5 and 3 (w/v)% of kappa C . Elasticity properties such as stress, strain and compressive elastic modulus, S of these composite gels were studied in various kappa C content and at several temperatures. The content and temperature dependence of the compressive elastic modulus, S of the swollen PAAm-kappa C 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 kappa C, and then increase by increasing kappa C 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 kappa C content and temperature. It is observed that the compressive elastic modulus increased when temperature is increased up to 40 degrees C and then decreases below this temperature for all composite gels. However, PAAm-kappa C composite gel presented lower values for the compressive elastic modulus, showing a minima at 40 degrees C for 1 (w/v)% of kappa C content gel.