Formation of the gamma phase in oriented isotactic polypropylene with varying stereoregularity

摘要: Structural transformations have been studied in oriented samples of isotactic polypropylene with various contents stereodefects. With the use small- and wide-angle X-ray diffraction, it was found that a stretched film contains small defective crystallites α phase an axial orienta tion. The γ is formed significant amount stereodefects during high-temperature annealing near melting point owing to epitaxial crystallization partial melt on residual crystallites. clearer this process expressed, lower degree crystallinity and/or higher stretching samples. An increase initial material expressed appearance second long period, which associated formation lamellar phase.