A novel shape memory poly(ε‐caprolactone) network via UV‐triggered thiol‐ene reaction. Issue 8 (1st April 2017)

• Record Type: Journal Article
• Authors: Yang, Pengfei; Zhu, Guangming; Xu, Shuogui; Zhang, Xiaoyan; Shen, Xuelin; Cui, Xiaoping; Gao, Yuliang; Nie, Jing
• Is Part Of: Journal of polymer science. Volume 55:Issue 8(2017)
• Page Start: 692
• Page End: 701
• Publication Date: 2017-04-01
• Subjects: crosslinking -- crystallization -- PCL networks -- shape memory polymer -- silicas -- thermal properties; 547
• DOI: 10.1002/polb.24314
• Languages: English
• ISSNs: 0887-6266

Abstract

ABSTRACT: A facile method to prepare shape memory polymers crosslinked by SiO2 is described. A series of biodegradable shape memory networks were obtained through thiol‐ene reaction triggered by UV irradiation between surface‐thiol‐modified SiO2 nanoparticles and end‐acrylate poly (ε‐caprolactone) (PCL). The highly selective thiol‐ene reaction ensured a uniform distribution of PCL chains between crosslinkers, contributing well‐defined network architecture with enhanced mechanical and shape‐memory properties. Thiol‐functionalized silica nanoparticle was characterized by using FTIR and XPS analysis, and 1 H NMR spectra was used to confirm the successful modification of terminal hydroxyl group of PCL diol. Surface‐modified silica particles were found well dispersible in acrylate‐capped PCL supported by SEM. Thermal and crystalline behaviors of the obtained polymers were analyzed by DSC and XRD, and DMA measurement proved good mechanical property. The shape memory behavior and tensile strength was somewhat tunable by the length of PCL. Acceptably, sample SiO2 ‐SMP2k presented 99% recovery ratio and 97% shape fixity, and its relatively high tensile strength showed an attractive potential for biomedical application. Finally, a possible molecular mechanism accounting for the shape memory property was illustrated. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2017, 55, 692–701 Abstract : A new synthetic method to obtain shape memory poly(ε‐caprolactone) (PCL) crosslinked by SiO2 nanoparticles (NPs) via photo‐initiated thiol‐ene reaction is described. Thiol‐ene network features a uniform distribution of PCL chains with desirable shape memory properties. The melting transition temperature is tuned by varying the molecular weight of the PCL prepolymer. SiO2 not only serves as crosslinker, but also can increase the mechanical strength.