X-RAY-DIFFRACTION COMPARATIVE-STUDY OF POLY(3-DECYLTHIOPHENES) AND POLY(4,4'-DIDECYL-2,2'-BITHIOPHENES)

The X-ray diffraction measurements have been done for PDTs and PDDBTs. Rather unexpected differences between diffraction patterns obtained; it seems, that the samples with the higher ordered, stereoregular chain (PDDBT) are less ordered in planes containing polymer chains than the samples with random arrangement of the side chains (PDT). We suggest that this effect may be connected with the differences between the molecular conformations of both polymer systems. This suggestion is confrontated with the computed diffraction spectra obtained for the model structures with the well defined molecular conformation.