Research on Shape Memory Performance of TPI/PE Composite Materials

Triple shape memory materials have become a major research hotspot in recent years. Trans-1,4-polyisoprene (TPI) was mixed with inexpensive polyethylene (PE) in this work, and TPI/PE shape memory polymer composites (SMPCs) were vulcanized using the dynamic vulcanization process. PE can be divided into low-density polyethylene (LDPE) and high-density polyethylene (HDPE), both have the same structure but different molecular chain arrangement and density. Since the properties of SMPC are different due to the different ratios of TPI and PE components, choosing the right ratio is especially important for triple shape memory materials. We investigated the triple shape memory properties of composites of TPI with LDPE and TPI with HDPE at different ratios (8:2,7:3 and 6:4), respectively. The impact of the dynamic vulcanization system on the mechanical and shape memory characteristics of the TPI/PE hybrid SMPC was discovered through a sequence of studies. The results showed that when the ratio of TPI/PE was 8:2, the composites had the fastest vulcanization rate and the largest cross-linking degree with the highest tensile strength and mechanical properties. In addition, the test results show that the crystalline properties of HDPE-based composites are consistently higher than those of LDPE-based composites. The shape memory properties of TPI/HDPE composites are more excellent than those of TPI/LDPE composites at the same ratio. The best triple shape memory properties were obtained at a TPI/HDPE composite ratio of 8:2. We believe that the relevant findings of this study can provide a valuable design reference for the development of high-performance TPI shape memory materials.