Bio-based adenine-containing copolyimides with high switching temperatures and high-strain storage†
High switching temperature shape memory polymers were developed from copolyimides via a facile random copolymerization strategy. Copolyimides with different copolymerization ratios were obtained and their shape memory properties were found to be different. API3 possesses excellent shape memory performance after one shape memory cycle (shape recovery Rr = 100%, tensile strain ε = 358%), higher than most previously reported materials. The shape memory properties of API3 are also outstanding (Rr = 100%, ε = 142%) after four consecutive shape memory cycles. To the best of our knowledge, this work presents a case for a linear polymer that enables the storage of high strain with full recovery and a high switching temperature (>260 °C). Tuning the macromolecular structure and supramolecular interactions thus provides a promising route to a high-performance shape memory polymer.