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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]

The wood is considered a natural composite of extreme complexity, mainly composed of cellulose, lignin, hemicellulose (polyposis), and extractives. Its composition encourages biological attacks from different species. In this context, several techniques have been studied and applied for disinfecting and decontaminating wood-made works of art and cultural heritage objects, which have been damaged by fungi, bacteria, and insects. Gamma radiation has been studied as an alternative to chemical methodologies for this purpose. By this way, the aim of this article is to illustrate the effect of gamma radiation on some physicochemical properties of Pinnus patula, Pinnus cunninghamia, Cedrella fissillis, and Ocotea porosa wood species. The irradiation has shown itself to be a fast and efficient process to eliminate infestations by both insects and microorganisms and no quarantine is required because of the no generation of toxic residues. On the other hand, this process does not protect the irradiated material from re-infestations or re-contamination. In this study, relatively high gamma radiation doses were applied up to 100 kGy so that radiation effects, which are cumulative, could be retrieved by means of thermal properties. The results have shown that gamma radiation, in the studied dose range, does not promote meaningful alterations on the evaluated properties, which allows that artifacts be irradiated multiple times, even if a re-infestation occurs. [ABSTRACT FROM AUTHOR]