Characterization of the Commercial Rubber Band as a Shape Memory Smart Material by Swelling Process with Fused Stearic Acid

Abstract

This study attempted to focus the light on the characterization possibility of the vulcanized, chlorinated, natural rubber products (as the commercial rubber band used in this study) as a shape memory smart material in the case of impregnating it with fused stearic acid by swelling mechanism. Where in this study, the ability of the commercial rubber band on fixing the stretching strain chosen in this study which is of 70% after removing the applied load off the rubber band, was measured after impregnating it with stearic acid (SA) material of weight ratio (30.4%) and swelling time=2hr. At the same time, measuring the ability of that rubber band on rid of this mechanical deformation once it is thermally stimulated and returning to its original shape (before the deformation) by subjugating it to the hot classical shape memory cycle (based on normal cooling at room temperature) with its two stages represented by the shape memory effect (SME) property activation and deactivation stages. Also, the techniques of differential scanning calorimetry (DSC) and x-ray diffraction (XRD) were used to know the agreement between these tests and the SME property test results (thermomechanical cycle test). Through the practical results of all the tests depending on the diagnosis, it was shown that the direct responsibility for the characterization of the commercial rubber band as a shape memory smart material is the stearic acid (SA) material, which acted as a lock in the rubber band structure that can be opened and closed with a temperature change within the melting range of (SA).