TY - JOUR
T1 - Crystallization of PVDF in the PVDF/PMMA blends precipitated from their non-solvents
T2 - Special orientation behavior, morphology, and thermal properties
AU - Zhao, Xuejuan
AU - Chen, Shuangjun
AU - Zhang, Jun
AU - Zhang, Wei
AU - Wang, Xiaolin
PY - 2011/8/1
Y1 - 2011/8/1
N2 - The poly(vinylidene fluoride) (PVDF)/poly(methyl methacrylate) (PMMA) blends were prepared by precipitation (or solution casting) in non-solvent ethanol, good solvent N,N-dimethylformamide (DMF), or DMF/ethanol mixed solvents. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses revealed that the crystalline phases of PVDF in the blends depended on the ethanol content in mixed solvents. PVDF crystallized into β phase when ethanol content was ≤60% (by volume, same hereinafter), instead, α and β phases existed together at ethanol content ≥70%. Correspondingly, different crystallization morphology of PVDF was observed from scanning electron microscopy (SEM) images, due to the transition from good solvent to non-solvent as ethanol content increased. Interestingly, special orientation behavior of PVDF was observed by XRD measurements for the (0 0 2) reflection of the α phase precipitated in the non-solvent DMF/ethanol=3/7 [DE37]. The PVDF in the blend precipitated in the non-solvent [DE37] also had a relatively high degree of crystallinity of 74.8%, according to DSC measurement. The investigation into the crystallization of polymer in non-solvent may attract certain interest, due to the interesting phenomena that occurred in the special solvent environment.
AB - The poly(vinylidene fluoride) (PVDF)/poly(methyl methacrylate) (PMMA) blends were prepared by precipitation (or solution casting) in non-solvent ethanol, good solvent N,N-dimethylformamide (DMF), or DMF/ethanol mixed solvents. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses revealed that the crystalline phases of PVDF in the blends depended on the ethanol content in mixed solvents. PVDF crystallized into β phase when ethanol content was ≤60% (by volume, same hereinafter), instead, α and β phases existed together at ethanol content ≥70%. Correspondingly, different crystallization morphology of PVDF was observed from scanning electron microscopy (SEM) images, due to the transition from good solvent to non-solvent as ethanol content increased. Interestingly, special orientation behavior of PVDF was observed by XRD measurements for the (0 0 2) reflection of the α phase precipitated in the non-solvent DMF/ethanol=3/7 [DE37]. The PVDF in the blend precipitated in the non-solvent [DE37] also had a relatively high degree of crystallinity of 74.8%, according to DSC measurement. The investigation into the crystallization of polymer in non-solvent may attract certain interest, due to the interesting phenomena that occurred in the special solvent environment.
KW - A1. Solvents
KW - A1. X-ray diffraction
KW - A2. Growth from solutions
KW - B1. Polymers
UR - http://www.scopus.com/inward/record.url?scp=79960561755&partnerID=8YFLogxK
U2 - 10.1016/j.jcrysgro.2011.06.036
DO - 10.1016/j.jcrysgro.2011.06.036
M3 - 文章
AN - SCOPUS:79960561755
SN - 0022-0248
VL - 328
SP - 74
EP - 80
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
IS - 1
ER -