Shape memory epoxy composites with high mechanical performance manufactured by multi-material direct ink writing

Using 3D printing to manufacture shape memory polymers (SMPs) becomes popular, since the technique endows SMPs the ability to shape into desired structures according to their applications. Among various types of SMPs, epoxy-based shape memory polymer and their composites are known for their high modulus and strength. However, limited by their rheological behavior, it is still hard to prepare high-quality printable epoxy materials. Here, by carefully tuning of rheological properties, we can prepare printable ink showing good shape retention, excellent mechanical performances below and above the glass transition temperature of epoxy, as well as good shape memory effect. The prepared ink can also be suitable for printing 3D models with spanning structures by the multi-material direct ink writing technique, which extends potential applications of epoxy inks in shape memory and other fields.