The surface of natural Brazilian amazonic fibers (curauá, Ananas erectifolius) was modified with polyaniline nanoparticles, through in situ preparation of polyaniline nanoparticles in presence of the curauá fibers. This allowed for a significant increase in the electrical conductivity of the fibers (≈2 500 times). As the electrical resistivity of the modified fibers is a function of the applied external pressure, the produced composites can be used as a cheap pressure‐sensing material. The modified materials were also characterized by FT‐IR, XPS and SAXS, and the obtained results were used to explain some of the observed characteristics of the materials.magnified image

Cardanol‐furfuraldehyde/maghemite composites were prepared through a bulk polymerization aiming to produce magnetic green resins able to absorb petroleum spilled on the water. Several techniques such as Fourier transform infrared spectroscopy, ultraviolet–visible spectrophotometry, wide angle X‐ray scattering, and small angle X‐ray scattering were used in the characterization of the materials. In addition, magnetic force and oil removal capability tests were also performed. Obtained materials presented a good magnetic force allied with a considerable oil removal capability: each gram of the resin was able to remove 10g of petroleum from the water. Therefore, the easy and simple production process presented is a promising tool for oil spill cleanup process. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

A magnetic resin based on lignin produced using the Kraft process was prepared and characterized. The material, because of its aromatic/aliphatic balance, can be used in oil-spill clean-up processes. The resin was prepared through bulk polycondensation of lignin, cashew nutshell liquid, and formaldehyde in the presence of maghemite nanoparticles. The obtained magnetic composites were studied by Fourier transform infrared spectroscopy, X-ray diffraction, and Small-angle X-ray scattering. Cure degree, magnetic force, and oil removal capability tests were also performed. The results show that the composites possess an elevated cure degree, besides a considerable magnetic force. The materials exhibit a good oil removal capability-the composite containing 3.3 vol % of maghemite can remove 11 parts of oil from water. V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 126: E304-E311, 2012

Cardanol, a well known natural resource, was used to produce a polymer resin in the presence of formaldehyde, catalyzed by H2SO4. Before reticulation, PAni · H2SO4 was blended with the resin. The blended material was cast into poly(propylene) cups and kept inside a desiccator under vacuum until complete water evaporation. The final in situ polymer blend was solid and could not be dissolved in ordinary solvents, indicating that a reticulated material had been obtained. Samples prepared similarly were then characterized, showing that the produced blends can be used as pressure sensing materials.magnified image