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Poly(vinylidene fluoride)/polyaniline blends of different composition were synthesized by chemical polymerization of aniline in a mixture of Poly(vinylidene fluoride) and N,N-dimethylformamide and their thermal and mechanical behavior was investigated as a function of the polyaniline doping level and the composition using thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis and tensile tests techniques. The results showed the blend obtained presents a good thermal stability with low weight loss up to 300 °C, assigned to water and solvents evaporation. The glass transition and melting point is not affected by the PANI content in the blend, showing that polymers are no miscible. The films produced present a good sustainability; however the presence of the conducting polymer in the blend increases the tensile strength and the Young modulus, while diminishes the elongation at break, as compared to pure PVDF.

Flexible, free-standing piezo and pyroelectric composite with 0 to 3 connectivity was made up from Lead Zirconate Titanate (PZT) powder and poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) copolymer. The pyroelectric and the piezoelectric longitudinal (d33) coefficients were measured. A 50/50 vol.% PZT/PVDF-HFP composite resulted in piezo and pyroelectric coefficients of d33 = 25.0 pC/N and p = 4.5 × 10-4 C/m²K at 70 °C, respectively. Analysis of the complex permittivity in a wide range of frequency was carried out indicating lower permittivity of the composite in comparison with a permittivity of the PZT ceramic. The low value of the permittivity gives a high pyroelectric figure of merit indicating that this material can be used to build a temperature sensor in spite of the lower pyroelectric coefficient compared with PZT

This study proposes a novel solution blow spinning technique (SBS) for fabricating YBCO ceramic nanofibers. The precursor solutions were obtained from Y, Ba, and Cu metallic acetates (Ac) and poly(vinyl pyrrolidone) (PVP, Mw = 360,000). Ac:PVP concentrations of 1:1 and 5:1 were tested, resulting in ceramic nanofibers with average diameters of 359 and 375 nm, respectively. X-ray diffraction confirmed the formation of a pure phase of YBa2Cu3O7-x. This is the first study to use SBS for fabricating YBCO nanofibers, and this technique shows promise for obtaining high-quality ceramic materials.

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This work reports a systematic comparative study of the technological properties of natural lattices and rubbers extracted from Hancornia speciosa Gomes and Hevea brasiliensis [(Willd. ex Adr. de Juss.) Muell.-Arg.] (clone RRIM 600) trees from 11 collections in Brazil throughout 2004. Natural rubber latex particle sizes and distributions were quite similar with an average diameter around 1 lm. Molecular weight, Wallace plasticity, and Mooney viscosity values were approximately the same for both rubbers. Fourier transform infrared spectroscopy peaks characteristic of natural rubber were observed for both Hancornia and Hevea. The measured differences in technological properties included lower values for Hancornia dry rubber content, % ash, % nitrogen, and plasticity retention index but higher value for acetone extract. Interestingly, nitrogen and protein content were much lower in Hancornia, suggesting that it may have important applications in nonallergic rubber uses. This represents the first report of lacticifer-produced low-protein natural rubber. V

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