CHAIN ALIGNMENT IN POLY(P-PHENYLENE VINYLENE) ON ORIENTED SUBSTRATES

We show that conjugated polymers processed via soluble precursor polym ers can be oriented by forming them on highly-oriented poly(tetrafluor oethylene), PTFE. The oriented PTFE induces preferential orientation o f the precursor polymers which is preserved and possibly enhanced duri ng the thermal conversion to the final conjugated polymer. Orientation is substantially better if precursor polymers are used which have a s ome content of stiff segments in their backbone. We characterise the s tate of alignment of the polymer by polarised optical absorption measu rements. We consider that orientation is confined to a thin layer adja cent to the substrate, and find from the form of the interband absorpt ion that the extent of conjugation is enhanced in this oriented region .