DRAWING AND ORIENTATION DEVELOPMENT OF AROMATIC POLYESTERS CONTAININGTERPHENYL UNITS IN THE MAIN-CHAIN AND ALIPHATIC SIDE-CHAINS

A range of aromatic polyesters containing terphenyl units in the main chain and alkyl side chains have been investigated with respect to the ir structure and orientation development. As-cast films showed a layer ed structure: layers of the main chains were preferentially organized parallel to the film surface. Upon drawing of these films, the structu re changed to a fibre-symmetric one, as was proven by wide-angle X-ray diffraction (WAXD). Possible morphologies, which are based on WAXD an d Raman data, are proposed. The development of the orientation with dr aw ratio appeared to be extremely efficient, even more efficient than that according to the affine deformation model. This was explained by the fact that the affine model assumes thin rods, whereas in reality, the orientation of units with a considerable thickness takes place. Co pyright (C) 1996 Elsevier Science Ltd.