Molecular dynamics and microstructure development during cold crystallization in poly(ether-ether-ketone) as revealed by real time dielectric and x-ray methods

The isothermal crystallization process of poly(ether-ether-ketone) from the glass has been studied in real time by dielectric spectroscopy and x-ray s cattering experiments. The combination of these two techniques revealed a c omplete picture of the crystallization processes from the point of view of both amorphous and crystalline phases. Analysis of results shows that the s ample morphology consists of lamellar stacks, separated by rather broad amo rphous regions. The lamellar stacks are highly crystalline (similar to 70%) , as obtained from both dielectric and x-ray scattering measurements, and t he amorphous phase within the stacks is constrained up to a level where no segmental relaxation is possible. The remaining amorphous phase, after comp letion of the primary crystallization process, still has a certain mobility , but it is significantly slower than the initial amorphous mobility. Diele ctric data and x-ray results are found to be highly congruent. (C) 2001 Ame rican Institute of Physics.