Fully oriented non-fibrous crystalline polyacetylene

Summary

The preparation of fully oriented non-fibrous crystalline polyacetylene is demonstrated. Poly-7,8-bis-(trifluoromethyl)-tricyclo-[4.2.2.0]-deka-3,7,9-triene, poly-(BTFM-TCDT), is polymerized by a ring opening metathetical polymerization. Films cast from a solution of poly-(BTFM-TCDT) (precursor polymer) can be converted to polyacetylene by heating. During this conversion process an uniaxial stress is applied to the precursor polymer film which results in a high orientation of the polymer chains. SEM pictures show a compact and homogeneous morphology, whereas sharp and well defined electron diffraction (HEED) patterns indicate a fully oriented crystalline transpolyacetylene material. Consequently we present polarized infrared spectra, expecially for the C-H out-of-plane deformation vibration (1010 cm⁻¹), which exhibit a tremendous dichroism for infrared radiation polarized parallel and perpendicular to the chain axis (c-axis, orientation direction).