Preparation of liquid crystalline polymer networks containing a cinnamyl group in the main chain with tunable thermal actuation behavior. Issue 14 (30th May 2019)

• Record Type: Journal Article
• Authors: Li, Hang; Yang, Rong; Peng, Yating; Cao, Hongwei; Li, Jinchun
• Is Part Of: Journal of polymer science. Volume 57:Issue 14(2019)
• Page Start: 904
• Page End: 911
• Publication Date: 2019-05-30
• Subjects: actuator -- liquid crystal -- photocrosslinking -- shape memory; 547
• DOI: 10.1002/polb.24845
• Languages: English
• ISSNs: 0887-6266

Abstract

ABSTRACT: A series of liquid crystalline copolyesters (LCPs) with different concentrations of a photocrosslinking moiety have been synthesized by random polycondensation with 4, 4′‐bis(6‐hydroxyhexyloxy)biphenyl, 2‐phenylsuccinic acid, and 4‐(6‐hydroxyhexyloxy)cinnamic acid (6HCA). Multifunctional monodomain liquid crystal networks (LCNs) with considerable and tunable actuation behavior are obtained by postphotocrosslinking. The influence of the photocrosslinking moiety on the phase transition behavior of the LCP and actuation behavior of the LCN has been investigated. The results suggest that incorporating 6HCA suppresses the smectic phase of the LCP and decreases the nematic‐isotropic phase transition temperature. Moreover, the starting actuation temperature of the LCN decreases from 55 to 40 °C as the 6HCA reached 50%. In addition, the actuation force and storage modulus of the LCN actuators are enhanced by incorporating a high concentration of 6HCA. A 1.64 MPa contractile force can be achieved, and it can lift burdens 1300 times heavier than its weight when 50% 6HCA is incorporated into the LCP. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2019, 57, 904–911 Abstract : Monodomain liquid crystal networks (LCNs) with considerable and tunable actuation behaviors are obtained by adjusting the crosslinking moiety in the LCN. The LCN actuation temperatures decrease from 60 to 45 °C as the crosslinking monomer increases up to 50%. Moreover, the actuation force of LCN actuators is enhanced, and a 1.64 MPa contractile force can be achieved. In addition, the LCN actuator can lift burdens 1300 times heavier than its weight.