[20p-W242-1~16] 12.1 Fabrications and Structure Controls

[20p-W242-14] Thermotropically spontaneous deformation of uniaxially oriented main-chain liquid crystalline elastomers

〇Kazuyuki Hiraoka¹, Ryo Shinozaki¹, Shohei Sumitomo¹ (1.Tokyo Polytech. Univ.)

Keywords:liquid-crystalline elastomers,polymer networks,shape memory

We observed the spontaneous shape change of a uniaxially oriented liquid-crystalline elastomer composed of smectic main-chain liquid-crystalline polyesters in a cyclic heating-cooling process. Although the elastomer contracted by about 650% on heating up to the isotropic phase, the sample length recovered by about 450% on cooling to room temperature in the first heating-cooling process. In contrast, the elastomer exhibited completely reversible deformation in the second heating-cooling process. A nonlinear relationship between the orientational order parameter S and the strain λ was observed. The mechanism of the spontaneous thermotropic shape change is discussed.