Viscoelasticity of the polydomain-monodomain transition in main-chain liquid crystal elastomers

被引：61

作者：

Azoug, A. ^{[1
]}

Vasconcellos, V. ^{[1
]}

Dooling, J. ^{[1
]}

Saed, M. ^{[2
]}

Yakacki, C. M. ^{[2
]}

Nguyen, T. D. ^{[1
]}

机构：

[1] Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA

[2] Univ Colorado, Dept Mech Engn, Denver, CO 80202 USA

来源：

POLYMER | 2016年 / 98卷

基金：

美国国家科学基金会;

关键词：

Liquid crystal elastomers; Soft elasticity; Polydomain; Monodomain; Viscoelasticity; NEMATIC ELASTOMERS; STRESS-RELAXATION; PHASE-BEHAVIOR; ELASTICITY; NETWORK;

D O I：

10.1016/j.polymer.2016.06.022

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

The goal of this study was to explore the rate-dependent behavior of the stretch-induced polydomain-monodomain (PM) transition of a liquid crystal elastomer (LCE). The main-chain LCE was synthesized and then cross-linked in the nematic polydomain state. The PM transition caused a soft-elastic behavior, which was measured using uniaxial tensile tests at multiple strain rates and temperatures. The main finding was that we were able to apply the temperature-dependent shift factor determined for the small strain behavior and in the frequency domain to create master curves for the large-strain response in the strain rate domain. The soft elasticity phenomenon was absent from the stress-strain curve at equilibrium. The results also suggest that the relaxation mechanisms of the network, and not of the mesogen orientation, dominate the rate-dependent behavior. Finally, we observed a relatively slow recovery behavior, suggesting the presence of an additional slow relaxation mechanism. (C) 2016 Elsevier Ltd. All rights reserved.

引用

页码：165 / 171

页数：7

共 27 条

[1] Dual relaxation and structural changes under uniaxial strain in main-chain smectic-C liquid crystal elastomer [J].

Agra-Kooijman, Dena M. ;

Fisch, Michael R. ;

Joshi, Leela ;

Ren, Wanting ;

McMullan, Philip J. ;

Griffin, Anselm C. ;

Kumar, Satyendra .

PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2015, 17 (01) :191-199

[2]

[Anonymous], 2007, Liquid Crystal Elastomers

[3] Elasticity of polydomain liquid crystal elastomers [J].

Biggins, J. S. ;

Warner, M. ;

Bhattacharya, K. .

JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, 2012, 60 (04) :573-590

[4] Slow stress relaxation in liquid crystal elastomers and gels [J].

Clarke, SM ;

Terentjev, EM .

FARADAY DISCUSSIONS, 1999, 112 :325-333

[5] Texture evolution during the polydomain-monodomain transition in nematic elastomers [J].

Clarke, SM ;

Terentjev, EM ;

Kundler, I ;

Finkelmann, H .

MACROMOLECULES, 1998, 31 (15) :4862-4872

[6] Direct experimental evidence of time-temperature superposition at finite strain for an amorphous polymer network [J].

Diani, J. ;

Gilormini, P. ;

Arrieta, J. S. .

POLYMER, 2015, 58 :107-112

[7]

Ferry JD., 1980, VISCOELASTIC PROPERT, V3rd ed.

[8]

FINKELMANN H, 1981, MAKROMOL CHEM-RAPID, V2, P317

[9] Polydomain-monodomain transition in nematic elastomers [J].

Fridrikh, SV ;

Terentjev, EM .

PHYSICAL REVIEW E, 1999, 60 (02) :1847-1857

[10]

Gallani JL, 1996, J PHYS II, V6, P443, DOI 10.1051/jp2:1996190

← 1 2 3 →