Double Networks of Liquid-Crystalline Elastomers with Enhanced Mechanical Strength.


Type
Article
Change log
Authors
Lin, Xueyan 
Zou, Weike 
Terentjev, Eugene M  ORCID logo  https://orcid.org/0000-0003-3517-6578
Abstract

Liquid-crystalline elastomers (LCEs) are frequently used in soft actuator development. However, applications are limited because LCEs are prone to mechanical failure when subjected to heavy loads and high temperatures during the working cycle. A mechanically tough LCE system offers larger work capacity and lower failure rate for the actuators. Herein, we adopt the double-network strategy, starting with a siloxane-based exchangeable LCE and developing a series of double-network liquid-crystalline elastomers (DN-LCEs) that are mechanically tougher than the initial elastomer. We incorporate diacrylate reacting monomers to fabricate DN-LCEs, some of which have the breaking stress of 40 MPa. We incorporate thermoplastic polyurethane to fabricate a DN-LCE, achieving an enormous ductility of 90 MJ/m3. We have also attempted to utilize the aza-Michael chemistry to make a DN-LCE that retains high plasticity because of several bond-exchange mechanisms; however, it failed to produce a stable reprocessable LCE system using conventional ester-based reactive mesogens. Each of these DN-LCEs exhibits unique features and characteristics, which are compared and discussed.

Description
Keywords
40 Engineering, 4016 Materials Engineering
Journal Title
Macromolecules
Conference Name
Journal ISSN
0024-9297
1520-5835
Volume Title
55
Publisher
American Chemical Society (ACS)
Sponsorship
European Research Council (786659)
ERC H2020