The effect of organic clay on the properties of TPI/NR composite materials

TPI shape memory materials’ low flexibility and poor mechanical properties currently limit their use in a broader range of applications. Most scholars use high performance fillers to improve their mechanical properties. However, the cost of high-performance fillers is high. Therefore, the introduction of flexible natural rubber (NR) and low-cost organic clay (OC) into the trans-1,4-polyisoprene (TPI) matrix as the reinforcing phase. A new shape memory polymer— TPI/NR/OC, was prepared by mechanical melt blending.The effect of the changes of filler content on the thermodynamic properties of the composite materials were revealed by series of tests. The results showed that OC formed a homogeneous intercalation structure with the composite matrix, and OC promoted the crystallization of TPI, and part of OC was able to form physical entanglements with the molecular chains of the composites, which led to the improvement of mechanical and shape memory properties. The tensile strength of the composite at an OC dosage of 3.6phr was 19.9 MPa, with a shape fixity ratio of 97.9% and a shape recovery ratio of 96.8%. The relevant findings of this research may provide valuable design references for more areas of application of shape memory composites.