Competing Effects of Network Architecture and Composition on Polydomain Liquid Crystal Elastomers

Yang, D.T.; Zheng, C.W.; Chan, C.L.C.; Maguire, S.M.; Ostermann, E.C.; Davidson, E.C.; Yang, D.T; Zheng, C.W; Chan, C.L.C; Maguire, S.M; Ostermann, E.C; Davidson, E.C

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Competing Effects of Network Architecture and Composition on Polydomain Liquid Crystal Elastomers

Yang, D.T.; Zheng, C.W.; Chan, C.L.C.; Maguire, S.M.; Ostermann, E.C.; Davidson, E.C.

Macromolecules 59(3): 1293-1306

2026

ISSN/ISBN: 0024-9297

PMID: 41768457

Accession: 103921157

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Summary

Main-chain liquid crystal elastomers (LCEs) are synthesized to investigate the interplay of the composition and network structure on LCE nematic-to-isotropic (N-I) transitions. We focus on networks synthesized from liquid crystalline oligomers reacted with tri- or tetrafunctional nonmesogenic cross-linker molecules. We find that coupling between mesogens and the polymer backbone increases with the degree of cross-linking. However, this enhanced coupling competes with mesogenic dilution arising from the cross-linker molecules to determine the N-I transition temperature (T NI). When cross-linker molecules are dilute, the degree of cross-linking directly correlates to the change in T NI from the oligomer to LCE (ΔT NI) through mesogen-backbone coupling. In this regime, ΔT NI ranges from 2.9 to 12.2 °C and 2.9-13.9 °C for tri- and tetrafunctional cross-linkers, respectively. At high cross-linker concentrations, deviations from this linear relationship appear. Further, the fractional mesogen content within an oligomer chain induces molecular weight-dependent mesogenic dilution effects arising from the flexible spacer molecules. Analysis of the N-I transition peak reveals a maximum latent heat per gram of mesogen (ΔH NI,mes) for this system.

Competing Effects of Network Architecture and Composition on Polydomain Liquid Crystal Elastomers

Yang, D.T.; Zheng, C.W.; Chan, C.L.C.; Maguire, S.M.; Ostermann, E.C.; Davidson, E.C.

Macromolecules 59(3): 1293-1306

2026

Full-Text Article emailed within 1 workday

Summary

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