Kramer Dominic, Finkelmann Heino
Institut für Makromolekulare Chemie, Albert-Ludwigs Universität Freiburg, Stefan-Meier Str. 31, 79104 Freiburg, Germany.
Macromol Rapid Commun. 2011 Oct 4;32(19):1539-45. doi: 10.1002/marc.201100259. Epub 2011 Jul 22.
Smectic-A elastomers combine one-dimensional translational order of rod-like segments with the rubber elasticity of a polymer network. In recent years, detailed investigations were carried out on elastomers showing a global prolate chain conformation. In this communication, the first experiments on fluorinated SA elastomers exhibiting a global oblate chain conformation are presented, where the polymer chains are on average compressed along the layer normal of the lamellar phase structure. The mechanical anisotropy is studied by means of thermoelastic experiments and stress-strain measurements. For the first time, the layer compression modulus B of smectic elastomers is directly measured. B is significantly larger as compared to conventional low molar mass liquid crystals and decreases significantly with increasing local disorder introduced by the isotropic crosslinker.
近晶A弹性体将棒状链段的一维平移有序性与聚合物网络的橡胶弹性结合在一起。近年来，对呈现整体长链构象的弹性体进行了详细研究。在本通讯中，展示了对呈现整体扁链构象的氟化近晶A弹性体的首次实验，其中聚合物链平均沿层状相结构的层法线方向被压缩。通过热弹性实验和应力应变测量研究了力学各向异性。首次直接测量了近晶弹性体的层压缩模量B。与传统的低摩尔质量液晶相比，B显著更大，并且随着由各向同性交联剂引入的局部无序度增加而显著降低。
