Inhibited-nanophase-separation modulated polymerization for recoverable ultrahigh-strain biobased shape memory polymers

Biobased shape-memory polymers with high strain and full recoverability have huge potential in biomedical applications. Herein, reversible ultrahigh-strain biobased shape-memory polymers are preparedviaan inhibited-nanophase-separation modulated polymerization strategy. A model polymerization system, citric acid (CA) and 1,10-decanediol as the rigid skeleton and switcher is selected, respectively, while 1,4-butanediol (BD) is used to tune the phase structure in the monomers. The nanomechanical investigation suggests that nanophase separation in the obtained polymers could be subtly suppressed by varying the dose of BD. In particular, poly(1,4-butanediol/1,10-decanediol-co-citric acid) with 7 mol% BD (7%-PBDC) shows an ultrahigh strain of 770% and a high reversibility rate of 98% in a complex origami configuration. In addition, the well-defined bio-inspired micro/nano-structures are fabricated on the PBDC surface by a lithography-free method, which allows for wide-range reversible wettability tunability from a highly hydrophobic state to a hydrophilic state, paving a promising pathway for intelligent skin with unique water collection or/and repulsion capability.