Postpolymerization alignment of bulk conjugated polymers

We have demonstrated postpolymerization stretch alignment of substituted conjugated polymers as evidenced by polarized infrared spectroscopy, with a Hermans orientation function value of 0.66 for a stretch ratio of 3.7. The effects of stretch rate and substrate on the material order are examined. We further show that the stretch-induced increase in long-range order leads to an increase in photoconductive response parallel to the stretch direction, and a decrease in the orthogonal direction. The introduction of small amounts of substituted fullerenes does not interfere with the ordering of the polymer on a bulk scale. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2978247]