Rheology and Optical Properties of Thermotropic Liquid Crystalline Polymers

热致液晶聚合物(TLCP)的新应用目前由于缺乏对液晶状态和凝固(向晶态转变)期间结构形成过程的了解而受到阻碍。这样的理解是控制机械、电学和光学性质所必需的，这些性质不仅取决于固有的分子性质，而且还取决于大尺度织构。这项研究涉及对TLCP在流变场和磁场中的结构的合作研究。光散射和显微镜(R.S.Stein)和流变学(H.H.温特)将应用于专门合成的样品(宝丽来)，并将利用实验室的磁场来产生必要的对准。中间纹理状态将通过施加定义明确的机械和电场来产生。对场诱导单区的研究将给出理解多区行为所需的本征性质(Miesowicz粘度、Frank弹性常数)。我们将研究天然多域和中间向错密度，为实际应用(设计合适的处理设备)以及多域TLCP的理论描述奠定基础。

Novel applications of thermotropic liquid crystalline polymers (TLCP) are currently prevented by the lack of understanding of the structure formation processes in the liquid crystalline state and during solidification (transition to the crystal state). Such understanding is required for controlling mechanical, electrical, and optical properties which not only depend on the intrinsic molecular properties but also on the large-scale texture. This research involves a cooperative study of the structuring of TLCPs in rheological and magnetic fields. Light scattering and microscopy (R.S. Stein) and rheology (H.H. Winter) will be applied to specifically synthesized samples (Polaroid) and the magnetic field of a laboratory will be utilized to create the necessary alignment. Intermediate textural states will be produced by applying well-defined mechanical and electrical fields. The study of the field induced monodomain will give the intrinsic properties (Miesowicz viscosities, Frank elastic constants) which are needed to understand the behavior of polydomains. The natural polydomain and intermediate disclination densities will be studied to lay the foundation for practical applications (design of suitable processing equipment) as well as for a theoretical description of polydomain TLCPs.