Open AccessStretch‐induced stable‐metastable crystal transformation of PVDF/graphene composites
Author(s) -
Guo Huilong,
Li Jingqing,
Meng Yanfeng,
Claville Christiansen Jesper,
Yu Donghong,
Wu Zhonghua,
Jiang Shichun
Publication year - 2019
Publication title -
polymer crystallization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.443
H-Index - 9
ISSN - 2573-7619
DOI - 10.1002/pcr2.10079
Subject(s) - materials science , recrystallization (geology) , small angle x ray scattering , composite material , lamellar structure , graphene , crystal (programming language) , crystal structure , crystallography , scattering , nanotechnology , optics , chemistry , paleontology , physics , computer science , biology , programming language
Abstract Deformation‐induced crystalline structure transformation of poly(vinylidene fluoride) (PVDF)/graphene composites from stable α‐crystal to metastable β‐crystal at different temperatures was investigated by means of in situ synchrotron radiation wide‐angle and small‐angle X‐ray scattering (SAXS). The obtained results of lamellar and crystalline structures during tensile deformation shown that the α‐β crystal transformation relies on the evolution of orientation and there is a threshold value (∼0.5) of orientation function for structure transformation. The mechanism of α‐β crystal transformation was interpreted based on an indirect approach via the intermediate state of tensile deformation‐induced fragmentation and recrystallization process. The fragmentation and recrystallization process was verified by the analysis of four‐point and then six‐point SAXS patterns. The formation of β‐phase at 160°C was confirmed as a “recrystallization (α‐crystal ‐) β‐phase transformation.” The loaded appropriate stress guarantees the stable‐metastable phase transformation of PVDF. While at 30°C, the adequate stress concentrated on the crystal phase results in formation of β‐crystal from the initial recrystallization. The addition of graphene is beneficial to enhance the mechanical property of PVDF at both 30°C and 60°C, but the compatibility of PVDF/graphene composites does not favor high temperature such as deformation at 160°C.