A photosensitive composition based on an aromatic polyamide for LCD 4D printing of shape memory mechanically robust materials

[Display omitted] •A composition based on MPA can be used for LCD printing of high-resolution objects.•Formation of crosslinked structures via the Michael reaction proceeds at ≥200 °C.•The materials are characterized by a high tensile strength (up to 92.4 ± 6.1 MPa).•The 4D-printed structures possess a good shape memory performance at Trec >150 °C.•The material maintains a good shape memory performance after being irradiated. High-temperature shape memory polymers (SMPs) draw growing interest from researchers due to their potential as materials for application in the field of high-temperature smart devices. However, in the majority of cases the processing of high-temperature SMPs is limited by fabrication of two-dimensional films. Here, we have prepared a photosensitive composition based on high-performance heat resistant poly-N,N′-(m-phenylene)isophthalamide (MPA) and photosensitive components (N,N-dimethylacrylamide and bisphenol A ethoxylate diacrylate (BAEDA)). It has been shown by IR spectroscopy, that LCD 3D printing followed by post-curing at 150 °C results in the formation of semi-interpenetrating polymer networks, while thermal processing at a temperature ≥200 °C leads to the formation of fully crosslinked structures due to the interaction of NH groups from MPA and acrylic groups from BAEDA via the Michael addition. The post-curing temperature has a significant effect on the thermal and mechanical properties of materials. Thermal post-curing of 3D printed samples at 250 °C for 1 h results in the fabrication of materials with the highest tensile strength (92.4 ± 6.1 MPa), glass transition temperature (148 °C) and thermal decomposition temperature (above 350 °C). Remarkably, MPA-based materials exhibit an excellent shape memory performance at temperatures >150 °C, with fixity ratio (Rf) of 99.7 % and recovery ratio (Rr) of 99.9 %. Moreover, we showed that the glass transition temperature decreased by no more than 1 % after γ-radiation of 200 Gy. In addition, the material maintains a high storage modulus and good shape memory performance after being irradiated, and thus has a great potential in the field of aerospace structural materials.