Jump to main content
Jump to site search

Issue 29, 2018
Previous Article Next Article

Thermomechanical properties of monodomain nematic main-chain liquid crystal elastomers

Author affiliations

Abstract

Two-stage thiol-acrylate Michael addition reactions have proven useful in programming main-chain liquid crystal elastomers (LCEs). However, the influence of excess acrylate concentration, which is critical to monodomain programming, has not previously been examined with respect to thermomechanical properties in these two-stage LCEs. Previous studies of thiol-acrylate LCEs have focused on polydomain LCEs and/or variation of thiol crosslinking monomers or linear thiol monomers. This study guides the design of monodomain LCE actuators using the two-stage methodology by varying the concentration of mesogenic acrylate monomers from 2 mol% to 45 mol% in stoichiometric excess of thiol. The findings demonstrate a technique to tailor the isotropic transition temperature by 44 °C using identical starting monomers. In contrast to expectations, low amounts of excess acrylate showed excellent fixity (90.4 ± 2.9%), while high amounts of excess acrylate did not hinder actuation strain (87.3 ± 2.3%). Tensile stress–strain properties were influenced by excess acrylate. Linear elastic behavior was observed parallel to the director with modulus increasing from 1.4 to 6.1 MPa. The soft elastic plateau was observed perpendicular to the director with initial modulus and threshold stresses increasing from 0.6 MPa to 2.6 MPa and 14 kPa to 208 kPa, respectively. Overall, this study examines the influence of excess acrylate on mechanical properties of LCE actuators.

Graphical abstract: Thermomechanical properties of monodomain nematic main-chain liquid crystal elastomers

Back to tab navigation

Supplementary files

Publication details

The article was received on 08 Jun 2018, accepted on 19 Jun 2018 and first published on 20 Jun 2018


Article type: Paper
DOI: 10.1039/C8SM01178H
Citation: Soft Matter, 2018,14, 6024-6036
  •   Request permissions

    Thermomechanical properties of monodomain nematic main-chain liquid crystal elastomers

    D. R. Merkel, N. A. Traugutt, R. Visvanathan, C. M. Yakacki and C. P. Frick, Soft Matter, 2018, 14, 6024
    DOI: 10.1039/C8SM01178H

Search articles by author

Spotlight

Advertisements