Nanocomposites and nanomaterials

Nanocomposites of polyaniline and polymethacrylic acid
Dutka V.S., Kovalskyi Ya.P., Khamar O.O., Halechko H.M.
Ivan Franko National University of Lviv, 6 Kyryla & Mefodia St., Lviv, 79005, Ukraine
e.mail: vdutka@ukr.net

Polymer-polymer composites (PPCs) based on electrical conductive polymer – polyaniline (PANI) and polymethacrylic acid (PMAA) have unique properties. Along with the electrical conductivity of the PPC can form films on different surfaces. Such composites can be successfully used for the design of chemosensors, protection of metals from corrosion, etc. Such PPC can be obtained by conducting oxidative polycondensation of aniline with peroxydisulfate of ammonium in the presence of PMAA. But this method does not allow you to control the exact relationship between the components. Another method of obtaining a PPC is a mechanical mixing of PMAA and PANI in a small amount of water and processing the resulting mixture by ultrasonic for 15 minutes. After drying the resulting composites, their physic-chemical properties were investigated.
The study of X -ray spectra of PANI and PMAA and composites on their basis showed that ligaments are formed between the components of the PPC. FTIR-spectroscopy and quantum-chemical calculations confirmed the possibility of forming hydrogen bonds between composite components. Different confirmation states of macromolecules of the PANI and PMAA lead to the formation of several types of hydrogen bonds, which are characterized by different energy and length.
The electrical conductivity of the resulting composites has been studied. The electrical conductivity depends on the ratio of the PANI and PMAA and is characterized by the maximum. The study of the dependence of electrical conductivity on the temperature allowed determining the energy of activation of charge transfer, which changes within quite wide limits.
The study of thermal destruction of the PANI, PMAA and PPC was carried out by thermal gravimetry. The destruction of the PMAA is stepped: when heated at temperatures of about 100 oC PMAA cleaves the water molecules when the deep destruction runs through. Moreover, the mechanism of decomposition runs both on the mechanism of destruction and depolymerization. The destruction of PANI is also in several stages. The PPC destruction is also stepped, but at slightly higher temperatures. Therefore, the components of the PPC have one on the other stabilizing influence.