PRECURSORS OF CRYSTALLIZATION VIA DENSITY-FLUCTUATIONS IN STIFF-CHAINPOLYMERS

The ordering process just before cold crystallization for a stiff-chai n polymer is studied by means of simultaneous real time wide- and smal l-angle x-ray scattering and dielectric spectroscopy techniques. The k inetics of the ordering process prior to crystallization is described by the spinodal decomposition formalism. From wide-angle x-ray scatter ing measurements it is confirmed that no crystalline order takes place during the induction period. The dielectric study of the alpha relaxa tion suggests that during this induction period there is not a major r estriction of segmental motions of polymer chain segments.