writer：Yaxin Qiu, Dheeman-Roy Munna, Fang Wang, Juqun Xi, Zhifeng Wang, Defeng Wu
keywords：photo-reversible networks; strain-induced crystallization; heterogeneity; biopolyester elastomer; shape-shifting pathway
source：期刊
specific source：Macromolecules, 2021, 54(12), 5694-5704
Issue time：2021年

For the shape-memory polymers (SMPs), introducing material heterogeneity is vital to tailor shape shifting pathways. However, it is hard to reprogram the heterogeneity for both the covalent networks and dynamic covalent networks after these networks are encoded. Herein, the photoactive coumarin derivative end-capped dangling chains were used to participate in building photo-reversible polycaprolactone/poly(malic acid) networks, endowing the networks with reprogrammable heterogeneity and capability of room-temperature storage of entropic energy. The alterations of network topology with 365 nm/254 nm UV-irradiations and the strain-induced crystallization behavior of as-prepared bio-based elastomers were studied, aiming at quantitatively guiding the spatiotemporal release of entropic energy to regulate asynchronous deformations. This work provides applicable methods to simplify shaping manipulation or to diversify shape-shifting pathways of SMPs.

https://pubs.acs.org/doi/full/10.1021/acs.macromol.1c00758