Nanocomposites and nanomaterials

Physical-chemical properties of composites based on polyaniline and water-soluble polymers
Dutka V.S., Aksimentyeva O.I., Kovalskyi Ya.P., Halechko H.М.
Ivan Franko National University of Lviv, 6, Kyryla & Mefodia str.
79005, Lviv, Ukraine,
E-mail: vdutka@ukr.net

Carry out of oxidizing polycondensation of aniline (AN) and its derivatives in the presence of water-soluble polymers: polyvinyl alcohol (PVA), polymethacrylic acid (PMAA), polyacrylic acid (PAA) and copolymer of styrene with maleic anhydride (PSTMA); allows to receive polymer-polymer composites (PPС) which have good electrical conductivity. Such composites can form films on surfaces of different nature, so they can use for the construction of various sensory devices.
We received PPC with a different content of polyaniline (PANI) in matrixes of water-soluble polymers. Increasing the content of PANI in the PVA matrix leads to increased electrical conductivity of the PPC. The growth of the proportion of conductive polymer in the matrix of PMAA and PAA also leads to an increase in electrical conductivity. The thermomechanical properties of PANI-PVA composites have been study. The growth of PANI in the composite results in decrease in the glass transition temperature of the polymeric material compared to PVA. For PANI and PSTMA composites, the glass transition temperature decreases with the increase of the conductive component compared to the pure PSTMA copolymer.
The interaction between the macromolecules PANI from PVA, PMAA and PSTMA were note for all studied PPCs. Given the strong polarization of macromolecules of PANI, one of the mechanisms for the formation of intermolecular polymer complexes is the formation of hydrogen bonds between the conductive polymer and the OH-groups of macromolecules PVA, PMAA and PSTMA. The method of IR spectroscopy confirmed the interaction between the macromolecules of the conductive polymer and PVA, PMAA and PSTMA.
The study of the morphology of the PANI-PVA composites indicates on influence of PPCs the composite on its structure. At small contents of PANI (before reaching the threshold of percolation), the conductive polymer is located in the dielectric polymeric PVA matrix in the form of not interconnected globular aggregates. With an increase in the content of PANI in the matrix, begin to form linear chains of conductive polymer. Upon reaching the percolation threshold (>2%), a grid of conductive polymer is formed in the matrix of PVA, which results in the achievement of high electrical conductivity.