Open AccessNovel characterization of the β → α crystalline phase transition of isotactic polypropylene through high‐temperature atomic force microscopy imaging and nanoindentation
Author(s) -
Tranchida Davide,
Kandioller Gottfried,
Schwarz Philipp,
Schaffer Walter,
Gahleitner Markus
Publication year - 2020
Publication title -
polymer crystallization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.443
H-Index - 9
ISSN - 2573-7619
DOI - 10.1002/pcr2.10140
Subject(s) - nanoindentation , tacticity , characterization (materials science) , materials science , atomic force microscopy , phase transition , recrystallization (geology) , microscopy , phase (matter) , polypropylene , nanotechnology , atmospheric temperature range , thermal , composite material , crystallography , chemical physics , thermodynamics , chemistry , optics , polymer , organic chemistry , physics , polymerization , paleontology , biology
The β → α crystalline phase transition of isotactic polypropylene takes place both upon raising the temperature and under high strains. This phenomenon is well known; however, this work contributes additional characterization, in particular through high temperature atomic force microscopy (AFM). In contrast to some results in the literature, the simultaneous presence of α‐ and β‐phases in the temperature range of the transition was observed. The recrystallization takes place very quickly and effectively. AFM imaging and nanoindentation has been performed at temperatures up to 160°C, providing a mechanical characterization that is not accessible through global methods like dynamic mechanical thermal analysis. The study also visualizes, to the best of our knowledge for the first time, the “α‐patches” predicted by Lotz.