Orientational order of a nematic polymer grafted on polytetrafluoroethylene

The orientation behavior of a nematic side-chain polymer grafted on polytet rafluoroethylene (PTFE) is studied. The sandwich-like composite was prepare d by the graft post-polymerization of 4-cyan-4'-(biphenyloxy)butyl acrylate on a PTFE film pretreated by vacuum ultraviolet irradiation (VUV). The ori ented liquid crystal layer was prepared by mechanical stretching of the com posite film . Orientation degree was measured by means of FT-IR spectroscop y. The orientation function increases with the increasing strain and attain s the upper limit value at the strain Delta l/l > 1.0. The temperature depe ndence of the orientation degree is completely reversible tinder cooling an d heating. Copyright (C) 2000 John Wiley & Sons, Ltd.