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The application of cashew gum, in particular the one which is abundant in northeastern Brazil, remains limited to the foods and pharmaceutics industry. In attempting to obtain further potentialities of the cashew gum (CG), its electrical applicability needs to be explored. To this end, the CG is incorporated in blends based on PANI to make an innovative thin self-sustainable blend films (PACG) comprising PANI and CG. The blend films were fabricated by adding the CG in the synthesis process of the polyaniline, and they were prepared by the standard "casting" method. The film materials were blending in three different weight ratios (99:1), (95:5) and (80:20). We also fabricated the only PANI film. As PANI has its conductivity enhanced by doping process, the blends and PANI films were doped by using sulfuric acid at 0.05 and 0.1 mol L−1 concentrations. The characterization of the films was carried out by FTIR spectroscopy, thermal analyses and electrical measurements. The FTIR results exhibited the occurrence of a weak and secondary chemical interaction between PANI and CG. Once there was no appearance of new bands, the profile of the FTIR curves was maintained for the blends and no significant shifts were identified for the maximum frequency of bands. The thermal analysis measurements revealed alteration at the thermal stability temperature of blends due to the doping process and indicated that the thermal profile of the constituent materials (PANI and CG) was preserved in the blends. The electrical studies showed that the undoped blend films exhibited a low level of conductivity as the amount of gum increased. On the other hand, the doped films reached a high level of conductivity in comparison with PANI films and the more the amount of CG in the blend the more is its conductivity. For PACG with 20% of gum, σ increased by a factor of 106, whereas in PANI film, it increased by 104 at the 0.1 mol L−1 doped level. These results point to the possibility of using this sort of blend based on polyaniline and cashew gum as an innovative conductive polymer once it exhibits acceptable electrical, structural and thermal properties. [ABSTRACT FROM AUTHOR]

Several composites and nanocomposites based on a polymeric matrix and ceramic fillers are being pursued for use as multifunctional and innovative materials. Nevertheless, there is a series of challenges to be solved in this area such as the understanding of the role of interfaces and the synergy between matrix and fillers. In this work, vulcanized natural rubber nanocomposites were prepared with different concentrations of two kinds of ceramic nanoparticles, potassium strontium niobate (KSrNbO or KSN) and nickel-zinc ferrite (NiZnFeO or NZF), synthesized by a chemical method known as the modified polyol method. Morphological and thermal characterizations were carried out by AFM, TG/DTG, TG/FTIR and DSC. The thermal properties of nanocomposites were compared and discussed as functions of concentration, type and surface of nanoparticles. The results obtained suggest that the base concentration for both types of nanoparticles inside the polymer matrix volume greatly adds to the increase in thermal stability up to 11 % and the glass transition temperature up to 10 °C. A similar evolution for the glass transition temperature ( T ), thermal stability temperature ( T ) and dielectric permittivity ( ε′) was identified, suggesting that these phenomena are mainly dominated by the same mechanisms. These results point to the possibility for the thermal parameter modulation in magnetic and ferroelectric nanocomposites by means of a suitable control of concentration and properties of the KSN and NZF nanoparticles. [ABSTRACT FROM AUTHOR]