Plastic deformation and subsequent crystallization of thin films of isotactic/atactic polystyrene (iPS/aPS) blends

Thin films of crystallized and non crystallized isotactic polystyrene (iPS) and its blends with atactic polystyrene (aPS) were deformed below their glass transition temperature T_g. Deformation occurs in a very narrow ‘deformation zone’ (λ = 4 nm) and the deformed material exhibits long range order independent of the crystallinity of the films till concentrations of aPS up to 15%. Films containing more than 20% aPS do not show long range order within the deformed material even after subsequent annealing above T_g. From these results, which were obtained by transmission electron microscopy and electron diffraction, the conclusion is drawn that the molecular processes of crazing in amorphous polymers and the high local deformation of polymer single crystals are obeying similar mechanisms.