Polarization properties of a novel oriented polydiacetylene

Polarized electronic absorption, Raman and luminescence spectra of gel-processed blends of a soluble polycarbazolyldiacetylene and ultrahigh molecular weight polyethylene are reported and compared with those observed in other physical states. The films are oriented by tensile drawing to a draw ratio of 62. The strong anisotropy of all the measured properties indicates a rather good orientation of the conjugated chains along the stretching direction. The data here presented are quite different from those described for other conjugated systems where the gel-processed stretch-oriented polyethylene chains play an important role in the improvement of the order and in the enhancement of delocalization for the conjugated guest. We attribute this peculiar behaviour to the stiffness of the conjugated skeleton.