Title: A Convenient Route to Prepare Reactive Azobenzene‐Containing Liquid Crystal Polymers and Photodeformable Fibers

Author: Yan Chen, Quan Liu, Patrick Theato, Jia Wei*, Yanlei Yu*

Journal: Adv. Intell. Syst., 2021, 3(10), 200054

Abstract:

Azobenzene‐containing liquid crystal polymers (azo‐LCPs) with reactive groups attract much attention due to the combined properties of liquid crystallinity, photoresponsivity and reactivity, which make them promising in designing intelligent photo‐driven soft actuators. Herein, a post‐polymerization modification strategy is used to prepare a series of reactive azo‐LCPs using the trans‐esterification reaction of poly(pentafluorophenyl acrylate) with functional alcohols. These reactive azo‐LCPs show good capabilities in fabricating fibers via a simple thermal‐drawing method and subsequent crosslinking reaction with diamine under mild conditions. Furthermore, the prepared fibers exhibit reversible deformation behaviors under the alternate irradiation of UV and visible light (365/530 nm). This facile synthetic strategy is expected to open up new possibilities for fabricating photo‐driven actuators.

Fulltext Link: https://onlinelibrary.wiley.com/doi/10.1002/aisy.202000254

In this paper, trans-esterification post-polymerization modification (PPM) of polypentafluorophenyl acrylate (PPFPA) containing functional alcohols provides a facile strategy to synthesize reactive azo-LCP. Due to the reactive pentafluorophenyl (PFP) ester in PPFPA fulfills a dual role: 1) it can be substituted by azobenzene group to endow the polymer with both liquid crystalline and photoresponsive properties, and 2) react with diamines to result in a crosslinked polymer network. Herein, utilizing a simple thermal-drawing of the azo-LCP and a subsequent crosslinking process, photodeformable fibers with reversible bending behavior were fabricated.