MOLECULAR-ORIENTATION IN COLD-STRETCHED POLY(PHENYLENE VINYLENE) FILMS

Oriented poly(phenylene vinylene) (PPV) films were prepared by pre-str etching sulfonium precursors in methyl alcohol at room temperature and annealing these at 180 degrees C. X-ray diffraction measurements show that the chain alignment and crystallinity in such PPV films increase with draw ratio. Preliminary conductivity measurements of these sampl es doped with ClSO3H appear to exhibit a similar dependence. This meth od of cold stretching, however, induces molecular orientation to a les ser degree than the more common technique of hot stretching, implying that swelling the precursor material in a polar solvent does not allow rates of strain as high as those accessed by heating.