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Phase transformation and dielectric properties of polyvinylidene fluoride/organic-montmorillonite nanocomposites fabricated under elongational flow field |
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| Authors: | Yizhang Tong Qilong Huang Guangjian He Xianwu Cao Zhitao Yang Xiaochun Yin |
| Affiliation: | 1. National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology, Guangzhou, China;2. National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology, Guangzhou, China Key Laboratory of Polymer Processing Engineering of Ministry of Education, South China University of Technology, Guangzhou, China Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, China |
| Abstract: | Compounding montmorillonite (MMT) with polymorphic polyvinylidene fluoride (PVDF) by melt intercalation method can induce the crystal phase transformation of PVDF, which is of great significance to obtain the electroactive PVDF. In this research, PVDF/Organic-Montmorillonite (OMMT) nanocomposites were prepared by a novel vane mixer, which was dominated by the elongational flow field in the whole plasticizing. The dispersion of OMMT, the crystal phase transformation of PVDF, and the resulting properties of nanocomposites were experimentally studied. The results of TEM and WAXD evidenced that homogeneous dispersion and desirable intercalation structure of OMMT were formed in the PVDF matrix under the effect of the elongational flow field. WAXD, FTIR, and DSC tests demonstrated that large amounts of β-phase of PVDF was formed due to the introduction of OMMT. The intercalation structure of OMMT and the crystal transformation of PVDF increased the dielectric constant and piezoelectric properties of nanocomposites, while the dielectric loss still maintained at a very low level. Finally, the effect of unique ''double-layer peeling'' mechanism of OMMT on the properties of nanocomposites was discussed. |
| Keywords: | crystal phase transformation dielectric properties elongational flow field montmorillonite polyvinylidene fluoride |