OH-modificd polypropylencs, PPOH, have intermolecular H-bonding between the OH groups that affect the polypropylene (PP) structure and influence its thermal properties. This paper discusses the effects of OH functionality on the crystalline structure and thermal properties of PPOH annealed in a partially melted state, which is typically used in the bixaxial orientation of PP for capacitor films. Biaxial orientation of PP improves its voltage breakdown strength . During the stretching process, changes occur in the morphology of the PP due to re-crystallization, which influences the ability to stretch the film and achieve suitable orientation of the crystals. In this study, recrystallization of PPOH were observed during annealing, which changed the thickness of the crystalline lamellae, but did not alter the a-monoclinic crystal structure. Thermal annealing produced kebab-like crystals and the amount of crystallinity decreased with increasing annealing temperature.