Regulating Asynchronous Deformations of Biopolyester Elastomers via Photoprogramming and Strain-Induced Crystallization
mediaposted on 04.06.2021, 20:31 by Yaxin Qiu, Dheeman-Roy Munna, Fang Wang, Juqun Xi, Zhifeng Wang, Defeng Wu
For shape-memory polymers (SMPs), introducing material heterogeneity is vital to tailor shape-shifting pathways. However, it is hard to reprogram the heterogeneity for both covalent networks and dynamic covalent networks after these networks are encoded. Here, photoactive coumarin derivative end-capped dangling chains were used to participate in building photoreversible polycaprolactone/poly(malic acid) networks, endowing the networks with reprogrammable heterogeneity and a capability of room-temperature storage of entropic energy. The alternations of network topology with 365/254 nm UV irradiation and 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 for simplifying shaping manipulation or for diversifying shape-shifting pathways of SMPs.