Thermally induced crystallization in glassy syndiotactic polystyrene

The thermal crystallization of glassy amorphous syndiotactic polystyrene has been studied using infrared, x-ray, and thermal analysis. The kinetics of the process is very rapid and the obtained crystalline phase is characterized by chains in zig-zag planar conformation. The use of the infrared analysis is indeed based on the presence of a skeleton band related to the zig-zag planar sequences. However infrared and x-ray data disagree in the evaluation of crystallinity, and a structural model has been proposed to account this experimental evidence. In particular the presence of a phase of intermediate order between amorphous and crystalline has been suggested. This mesomorphic phase is characterized by conformational order, and probably by crystalline order at very short range, both not sufficient to give rise to discrete x-ray diffraction patterns.