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.

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Polymer based materials with high conductivity and electric insulation are widely used in new electronic fields as thermal interface material (TIM). In this work, firstly we prepared the mixed fillers of silicon carbide (SiC) and carbon nanotubes (CNT), and then used them to modify silicone rubber (SR) preparing composite SR. The experimental results of TGA showed that the composite silicone rubber had strong thermal stability, and the mass loss was only 5% until about 370°C. Besides, the thermal conductivity was significantly enhanced, which increased from 0.2 (pure SR) to 1.103 W·m−1·k−1 (composite SR containing 3wt%CNT and 20wt%SiC), the enhancement ratio arriving as high as 483.05%. In addition, the composite silicone rubber maintained (water contact angle above 90 °) hydrophobicity and electrical insulation (volume resistivity of composite SR with 3wt%CNT and 20wt%SiC up to 1013 Ω·cm), which effectively prevent leakage risk and reduce voltage loss. Therefore, a small number of mixed fillers of SiC and CNT can effectively improve the combination properties of silicone rubber and provide more ideas for TIM.

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Insulating materials with high thermal conductivity have become the key to solving the internal heat problem of electronic components. In this study, two fillers were prepared by the in situ generation method. The uniform distribution of silicon dioxide (SiO2) nanoparticles and silver (Ag) nanoparticles on the surface of graphene oxide (GO) and silicon carbide (SiC) was proved by characterization methods such as micromorphology (TEM and SEM) and elemental analysis (XPS), respectively. The fillers above prepared were then added to silicone rubber (SR) to improve its thermal conductivity. SiO2 nanoparticles attached to the GO surface were compatible with the SR matrix, so the thermal resistance of the interface between the GO and the matrix was reduced. The thermal conductivity of Ag nanoparticles generated on the SiC surface was significantly better than that of SiC whiskers. Besides, the composite filler was more conducive to the formation of a heat conduction path, so the thermal conductivity of silicone rubber was improved. In addition, the composite SR maintained pleasing electrical insulating properties, and the volume resistivity of all samples was above 1013 Ω·cm. The prepared composite filler and composite SR provide ideas for developing high-performance thermally conductive and insulating polymers.