The structural effects of annealing time and temperature on the paracrystal‐crystal transition in isotactic polypropylene

Abstract

Abstract The influence of different annealing treatments on the crystalline order of isotactic paracrystalline polypropylene is described. The result support an intramolecular transformation mechanism based on a rewinding of hellcal segments of different lengths having opposite senses of spiralization. Such a mechanism is in agreement with the annealing time dependence of a particular order parameter and is sensitive to the temperature and not to the annealing time once the saturation order value is reached. This saturation phenomenon occurs very quickly at the higher temperatures.