Abstract This work aimed to obtain thermoplastic starch composites (TPS) derived from starch and fibers of babassu coconut. The (TPS) was prepared with 40% plasticizer (glycerol). The fibers underwent chemical treatment of alkalinization and bleaching. SEM images and infrared spectra showed that wax, lignin, and hemicellulose were removed from the fiber surface. SEM images of TPS starch showed a smooth and uniform surface, whereas images of the TPSWF composite (washed fiber) showed voids between the fiber and the TPS. This phenomenon was not observed in the SEM images of the composites TPSAF (alkalized fiber) and TPSBF (bleached fiber). The tensile strength and elastic modulus of the composites were higher than the pure TPS matrix. Concerning elongation, composites underwent less elongation than TPS. The mechanical properties found for the TPSWF and TPSAF composites do not differ. However, the mechanical properties of the TPSBF composite were better than the properties of the other composites.
This work described a new magnetic material enriched with strontium as catalyst to produce babassu biodiesel. The use of magnetic materials has attracted attention due to easy and fast separation from reaction medium. Moreover, they are ecologically correct, due to they generate less discards to the environment. Techniques of analysis and characterization were carried out to check the synthesis of magnetite and strontium ferrite, besides to verify the presence of hydroxide and carbonate in the structure of the strontium oxide. The best catalytic activities presented conversions of 78.6% and 89.7% when using the catalysts SrO/Fe3O4 and SrO/SrFe2O4, respectively. Density studies of the alkali active sites were performed to elucidate the best activity for the catalyst composed with SrFe2O4.
Hyperbranched biopolymers is an important class of polymer that is used in different areas, mainly in biomedicine. AB2 monomers are crucial to the development of a "hyperbranched" architecture of polyglycerol, being glycidol the most commonly used, even considering its environmental hazard. Glycerol carbonate is an ecologically accepted monomer synthesized directly from glycerol, and the chosen for the studies herein. In literature, no studies described the use of glycerol and cyclic carbonates to prepare hyperbranched polymers. This work describes the obtainment of hyperbranched polymers using glycerol and TMP salt as core-initiator and glycerol carbonate and propylene carbonate as monomers. The polymers were characterized by FTIR, NMR, MALDI-TOF and TEM. NMR spectroscopy showed linear, dendritic, and terminal units of hyperbranched polymer. The degree of branching PGLYGC and PTMPGC was 0.669 and 0.667, respectively. The molecular weight of PTMCGC, PTMPPC, PGLYPC was found and compared with MALDI. The molar mass was not different from the calculated by Inverse Gated. These polymers have enormous potential as drug delivery and an environmentally correct synthetic route due to the substitution of glycidol by biocompatible monomers.
This work proposed a procedure to examine ashes produced in burning lubricating oils used in public transportation, in Teresina PI. Sulphanilic acid was added to the oil samples, which were burned at 550 °C for three hours and 650 °C for two hours. The ash solutions were analyzed by FAAS and there were significant differences in the metal contents of the waste oil produced from normal car service. The quantification limits in μg g-1 were 5.9 (Fe), 4.4 (Pb), 1.7 (Ni), 2.1 (Cu), and 1.2 (Zn). The results showed positive accuracy and precision with recoveries between 88 and 108%, and RSD lower than 10%.
The objective of this work was to study the potentialities of Dipteryx lacunifera Ducke seeds oil for biodiesel production. The yield in oil was of 46.11 ± 0.37%. Methyl biodiesel was prepared by base catalyzed transesterification yielding 88.13% and percentage conversion of triglycerides to corresponding methyl ester of 89.1%. The addition of the tertiary butylhydroquinone (TBHQ, 50 ppm), butylated hydroxytoluene (BHT, 50 ppm) and cashew nut shell liquid (CNSL, 2000 ppm) antioxidants in the biodiesel contributed to the increase of the induction period of 2.97 h for 8.08; 6.06 and 6.02 h, respectively.
Biodiesel was obtained by transesterification of babassu oil in anhydrous ethanol and methanol, employing NaOH as catalyst. The products obtained were characterized by physico-chemical and thermogravimetric analysis. It could be concluded that the properties of the two types of biodiesel (ethanolic and methanolic) are very similar when compared with diesel oil.
A simple and reliable ashing procedure is proposed for the preparation of used lubricating oil samples for the determination of Zn, Fe, Pb, Ni and Cu by the flame atomic absorption spectrometry technique. Sulphanilic acid was added to oil samples, the mixture coked and the coke ashed at 550 ºC. The solutions of the ash were analysed by flame AAS for these metals. The quantification limits were 38.250 µg g-1 for Zn, 4.550 µg g-1 for Fe, 1.562 µg g-1 for Pb, 1.450 µg g-1 for Ni, and 0.439 µg g-1 for Cu. The determinations, in lubricating oil, showed good precision and accuracy with recoveries between 90 and 110 %, indicating a negligible matrix effect in the experiments using addition of analyte, with relative standard deviation lower than 5%. The results for analysis of wastewater contamined by theses lubricants showed a very high relative standard deviation.