The thermal behaviour of poly(3-octylthienylene) synthesized by an Ni-based catalyst: DSC, optical microscopy and XRD analyses

A detailed study on the thermal behaviour of two molecular weight fractions of poly(3-octylthienylene) (Mw = 13,000 and 24,000 by GPC) was performed using DSC, XRD and FTIR spectroscopies and optical microscopy. This polymer clearly shows a polymorphism involving two crystalline phases and a very stable mesophase, probably nematic. A structural model for a novel 3D phase, different from that so far observed, has been derived.