Random Liquid Crystalline Copolymers Consisting of Prolate and Oblate Liquid Crystal Monomers

• Published in: Macromolecules 2021-06, Vol.54 (12), p.5376-5387
• Main Authors: Xu, Yang, Dupont, Robert L, Yao, Yuxing, Zhang, Meng, Fang, Jen-Chun, Wang, Xiaoguang
• Format: Article
• Language: English
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/acs.macromol.1c00006

Interactions between side chains of polymers have been utilized to tune the thermal and mechanical properties of polymeric materials. In liquid crystal (LC) elastomers (LCEs), previous studies have demonstrated that the configuration of LC monomers, specifically oblate or prolate, determines the direction of macroscopic material deformations relative to the orientational ordering of the LC functional groups. However, the effects of the copolymerization between different configurations of LC monomers on the phase behaviors and thermomechanical properties of LCEs have not been explored. Here, we reveal that statistically random copolymers of LC monomers with different configurations destabilize the orientational order of the LC functional groups, whereas the random insertion of LC monomers with the same configuration preserves the packing of the constituent mesogenic functional groups. We further demonstrate how this fundamental understanding can be applied to control both the direction and magnitude of the thermally triggered mechanical deformations of LC copolymer networks.