Diversified α-phase nanostructure of isotactic polypropylene under cylindrical confinement via cross diffraction analysis. (28th September 2019)

• Record Type: Journal Article
• Authors: Zeng, Xingming; Zhang, Shuailin; Zheng, Nan; Yu, Shichen; Li, Xiaoguang; Ageishi, Masaki; Lotz, Bernard; Liu, Gengxin; Cao, Yan
• Is Part Of: Polymer. Volume 179(2019)
• Publication Date: 2019-09-28
• Subjects: i-PP nanostructure -- X-ray and electron diffraction -- Nanoscale confinement; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2019.121647
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Understanding polymer nanostructures is a prerequisite to manipulate their physical properties. Molecular self-assembly under confinement effectively generates novel polymer nanostructures. However, in one confined system, diffraction signals of different nanostructures are merged in a typical two-dimensional (2D) wide-angle X-ray diffraction (WAXD) measurement. For comparison, selected-area electron diffraction (SAED) of transmission electron microscopy can precisely capture the "local" diffraction signal of an individual nanoscale entity. Here, using isotactic polypropylene (i-PP) as a model polymer, we have demonstrated a cross-analysis of global X-ray and local electron diffraction results to fully reveal the structural details of i-PP nanorods. For the first time, we have decomposed completely the "mixed" 2D WAXD patterns of i-PP nanorods into five types of α-phase nanostructures: (a). Left-tilted daughter crystals; (b) Right-tilted daughter crystals; (c) Double-tilted daughter crystals; (d) a*-axis oriented crystals; (e) b-axis oriented crystals. Graphical abstract: Image 1 Highlights: Cross-analysis of electron and X-ray diffraction results in confined nanorods. Encircling an individual rod to obtain the local electron diffraction signal. Decomposed completely overlapped X-ray pattern of isotactic polypropylene nanorods. Five types of α-phase nanostructure are resolved under cylindrical confinement.