Ultra-high molecular weight pullulan-based material with high deformability and shape-memory properties

Most shape-memory polymers (SMPs) are derived from petroleum feedstocks, which have limitations due to their challenging manufacturing process. Accordingly, herein, a novel SMP based on microbially produced ultrahigh-molecular-weight (UHMW) pullulan was developed. UHMW pullulan cross-linked with 1,4-butanediol diglycidyl ether was wet-spun into fibers with high stretchability (1365 % strain) and excellent shape-memory properties. Furthermore, using three-dimensional (3D) printing, UHMW pullulan-based structures with highly complex shapes (for example, square, cruciform, pentagram and tubular structures), large deformability, and shape memory properties were fabricated. These 3D-printed structures exhibited four-dimensional (4D) programmable deformation under solvent stimulation, enabling the 4D printing of pullulan. The sustainable and eco-friendly approach proposed in this study for the production of pullulan-based SMPs promised to address the current limitations of petroleum-based SMPs.