▎ 摘　　要

In this work, poly(vinylidene fluoride) (PVDF)/graphene oxide (GO) were prepared through a two-step processing procedures, i.e. solution compounding and subsequent melt compounding processing. The thermal reduction of GO during the sample preparation process, the dispersion state of GO in the composites, and the crystallization of PVDF matrix were comparatively investigated. The results demonstrated that the partially reduced GO could be obtained during the sample preparation process. The residual oxygen-containing groups induced the crystal transformation of PVDF matrix from a-form to beta-form on one hand. On the other hand, there was specific interfacial interaction between oxygen containing groups of GO and >CF2 group of PVDF matrix. The PVDE/GO composites were still insulated. High dielectric constant and low dielectric loss were achieved for the PVDF/GO composites with GO content higher than 1 wt%. The mechanisms for the excellent dielectric properties were proposed to be related to the interfacial polarization of the partially reduced GO, the formation of polar beta-form PVDF crystallites and the formation of local GO network structure. (C) 2016 Elsevier Ltd. All rights reserved.