Mechanical properties and curing characteristics of shape memory natural rubber

Natural rubber, which is a polydiene elastomer, is one of the attractive raw materials that could be developed as a shape memory polymer because of its high mechanical and elastic properties. This study aims to determine mechanical properties and curing characteristics of heat-induced shape memory polymer of natural rubber or herein after referred to shape memory natural rubber (SMNR). Natural rubber with different blend ratios of sulphur was prepared by a two-roll mill. The curing characteristics were determined using Moving Die Rheometer at 150 degrees C. The effect of sulphur (0.75; 1.25; 1.5 phr) on mechanical properties such as tensile strength, tear strength and shape memory properties of the stearic acid swollen SMNR vulcanizates were investigated. This research showed that the higher sulphur amount gives the higher torque difference and higher mechanical properties. Shape memory compound swollen stearic acid exhibited shape recovery of 98-100% and shape fixity 59-88.5%.