Morphology, crystalline structure, and properties of poly(vinylidene fluoride)/silica hybrid composites

Abstract

Abstract Poly(vinylidene fluoride)/silica (PVDF/SiO 2 ) hybrid composite films were prepared via sol–gel reactions from mixtures of PVDF and tetraethoxysilane in dimethylacetamide. Their morphology, crystalline structure, and thermal, mechanical, and electrical properties were examined. For morphology measurements, scanning electron microscopy and optical microscopy were applied. X‐ray diffraction and infrared analyses showed that the crystalline structure of PVDF was not changed much by the addition of SiO 2 , indicating that there was no interaction between PVDF and SiO 2 . With increasing SiO 2 content, the melting temperature rarely changed, the degree of crystallinity and the dielectric constant decreased, and the decomposition temperature slightly increased. A PVDF/SiO 2 hybrid composite film with 5 wt % SiO 2 exhibited balanced mechanical properties without a severe change in the crystalline structure of PVDF, whereas for the hybrid composites with higher SiO 2 contents (>10 wt %), the mechanical properties were reduced, and the spherulite texture of PVDF was significantly disrupted by the presence of SiO 2 particles. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 40: 19–30, 2002