title: Design of Poly(L-lactide)-Poly(ethylene glycol) Copolymer with Light-Induced Shape-Memory Effect Triggered by Pendant Anthracene Groups.
abstract: A novel light-induced shape-memory material based on poly(l-lactide)-poly(ethylene glycol) copolymer is developed successfully by dangling the photoresponsive anthracene group on the PEG soft segment selectively. For synthesis strategy, the preprepared photoresponsive monomer N,N-bis(2-hydroxyethyl)-9-anthracene-methanamine (BHEAA) is first embedded into PEG chains; then, we couple this anthracene-functionalized PEG precursor with PLA precursor to result in PLA-PEG-A copolymer. The composition of target product can be well-defined by simply adjusting the feed ratio. The chemical structures of intermediate and final products are confirmed by (1)H NMR. Differential scanning calorimetry analysis of material reveals that the PEG soft segment became noncrystallizable when 4% or more BHEAA is introduced, and this feature is beneficial to the mobility of anthracene groups in polymer matrix. The static tensile tests show that the samples exhibit rubberlike mechanical properties except for the PLA-dominant one. The reversibility of [4 + 4] cycloaddition reaction between pendant anthracene groups in PLA-PEG-A film is demonstrated by UV-vis. Eventually, the light-induced shape-memory effect (LSME) is successfully realized in PLA-PEG-A. The results of cyclic photomechanical tests also reveal that the content of PLA hard segment as well as photosensitive anthracene moieties plays a crucial role in LSME.
authors.affiliation: Center for Degradable and Flame-Retardant Polymeric Materials, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University , Chengdu 610064, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.affiliation: Center for Degradable and Flame-Retardant Polymeric Materials, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University , Chengdu 610064, China.
authors.forename: Man-jie
authors.initials: MJ
authors.lastname: He
authors.affiliation: Center for Degradable and Flame-Retardant Polymeric Materials, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University , Chengdu 610064, China.
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Deng
authors.affiliation: Center for Degradable and Flame-Retardant Polymeric Materials, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University , Chengdu 610064, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Du
authors.affiliation: Center for Degradable and Flame-Retardant Polymeric Materials, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University , Chengdu 610064, China.
authors.forename: Cheng-Jie
authors.initials: CJ
authors.lastname: Fan
authors.affiliation: Center for Degradable and Flame-Retardant Polymeric Materials, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University , Chengdu 610064, China.
authors.forename: Ke-Ke
authors.initials: KK
authors.lastname: Yang
authors.affiliation: Center for Degradable and Flame-Retardant Polymeric Materials, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University , Chengdu 610064, China.
authors.forename: Yu-Zhong
authors.initials: YZ
authors.lastname: Wang
keywords: anthracene; light-induced; poly(ethylene glycol); poly(l-lactide); shape memory