Levchenko V. Structure and electro-physical properties of nanocomposites based on thermoplastic polymers and carbon nanotubes

The object of the research - the regularities of conducting phase formation of the filler and influence of its structural organization on the properties of the polymer nanocomposites. The aims of the thesis investigation are as follows: to determine the peculiarities of the formation of the filler conductive structure in polymer nanocomposites filled with carbon nanotubes (CNT) and combined nanofillers and to investigate the influence of the morphology of the heterogeneous structure of the composite and interaction of nanofillers on the electrical, dielectric, thermophycal and mechanical properties of the composites. The main results of this work were obtained by means of differential scanning calorimetry, dielectric relaxation spectroscopy, dynamic mechanical analysis and thermomechanical analysis methods. It has been shown that conductive polymer blends have a lower percolation threshold in comparison with individually filled polymers due to a concept of double percolation effect. It has been found that the simultaneous introduction of organo-modified clay (OMC) and CNTs into thermoplastic matrix provides a better distribution of carbon nanotubes, preventing their aggregation. This results in the decrease of the percolation threshold of composites PP/CNT. It has been shown that the formation of the conducting phase is more effective in the polymeric matrix with combined nanofillers CNT/nanometal in comparison with individual fillers. The obtained experimental results can be applied as a scientific basis for the search of the optimal conditions to form the structure of the conducting filler, which will enable to get the materials with necessary preassigned properties.