Investigation of crystallization kinetics of barium titanate doped PVDF composites

In the scope of thesis, it is aimed to prepare composites of barium titanate (BT) within polyvinylidene fluoride (PVDF) and investigate their structural, morphological and crystallization properties. In order to ensure the uniform dispersion of BT in PVDF and to increase the polymer matrix interaction, BT was modified with silane (BT-APS) and in addition, BT@PANI particles in core-shell structure were prepared by in-situ polymerization method. Nanoparticles were characterized by using FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-Ray Diffractometry), TEM (Transmission Electron Microscopy) and TGA (Thermal Gravimetric Analysis) methods. As a result it was investigated that BT was modified with silane and polyaniline (PANI) was successfully coated on the BT surface. PVDF based composites were prepared by solution casting method by adding BT, BT-APS and BT@PANI. Structural, physical and morphological properties of the prepared composite films were investigated by FTIR, XRD and SEM (Scanning Electron Microscopy) analyses. It has been proven that all BT-based additives have a decreasing effect on crystallization of PVDF. According to Avrami kinetic studies, n value was found to be between 1-2, and it was shown that PVDF and its composites performed surface nucleation and one-dimensional growth. Activation energy values obtained from Kissinger and Takhor models increased in direct proportion to the increasing concentration of additives in the composites. The activation energy of pure PVDF was lower than composites, which demonstrated that the composites had lower crystallization ability.