Study On Preparation Of Multi-Layer Co-Extruded PVDF Cast Composite Film

PVDF has been widely used in chemical, electrical, electronic and machinery industry and other industries, which has excellent weather resistance, UV resistance and mechanical properties. However, the hydrophilicity of PVDF is so poor that it's applications are limited, therefore, modifications of PVDF are necessary before used. This paper studied the influences of TiO2 and PMMA on the properties of PVDF films, prepared the PVDF multilayer composite films by multi-layer co-extrusion, and investigated the properties of the film.First, the raw materials have been selected according to requires of the casting process. The PVDF films are modificated by the way of blending, and the TiO2/PVDF blend films and PMMA/PVDF blend films are prepared. The performances of the blend films are discussed by the test including of the melt index (MI), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), contact angle, mechanical property test and so on. The results showed that some properties of the TiO2/PVDF blends film changed with the different contents of TiO2, such as the flow properties, crystalline properties, mechanical properties, hydrophilicity. The flow properties, processing properties, crystallization capacity, mechanical properties of PMMA/PVDF blends are also changed with the contents of PMMA. At last, the best experimental formula and co-extrusion process parameters are determined, moreover, the three-layer co-extrusion composite films are made through the co-extrusion cast method. The results showed that the properties of the three-layer co-extrusion composite films we prepared exhibited excellent performances as expected.