Reuse of sugarcane bagasse ash (SCBA) to produce ceramic materials

Sugarcane bagasse ash (SCBA) is a residue resulting from the burning of bagasse in boilers in the sugarcane/alcohol industry. SCBA has a very high silica concentration and contains aluminum, iron, alkalis and alkaline earth oxides in smaller amounts. In this work, the properties of sintered ceramic bodies were evaluated based on the concentration of SCBA, which replaced non-plastic material. The ash was mixed (up to 60 wt%) with a clayed raw material that is used to produce roof tiles. Prismatic probes were pressed and sintered at different temperatures (up to 1200 degrees C). Technological tests of ceramic probes showed that the addition of ash has little influence on the ceramic properties up to 1000 C. X-ray diffraction and thermal analysis data showed that, above this temperature the ash participates in the sintering process and in the formation of new important phases. The results reported show that the reuse of SCBA in the ceramic industry is feasible. (C) 2011 Elsevier Ltd. All rights reserved.

Understanding the Crystallization Mechanism of a Wollastonite Base Glass Using Isoconversional, IKP Methods and Master Plots

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thermomechanical characterization of PVDF and P(VDF-TrFE) blends containing corn starch and natural rubber

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análises térmicas e processo de sinterização da cerâmica KSr2Nb5O15 dopada com CuO

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

DSC studies on protein isolate of guava seeds Psidium guajava

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Physical properties of pectin-high amylose starch mixtures cross-linked with sodium trimetaphosphate

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

ZnO-TiO2 composite formed by mixed oxides via polyol

Among the researches on preparation and test of nanostructured materials, titanium dioxide and zinc oxide have been the most frequent studied oxides. In order to extend their properties, composites have been prepared using three different methods: Polyol Method, Sol-gel Process and a combination of the two processes (hybrid process). Recent research showed best properties in composite materials than in pure oxides. In this work is presented the preparation and the structural characterization of ZnO-TiO2 composite nanostructures to be tested for their performance in electrocatalysis and in further trial on photovoltaic cells.

Thermoanalytical study of purine derivatives compounds

Os métodos térmicos em análises estão sendo atualmente muito utilizados nas investigações cientificas. Neste trabalho a termogravimetria-análise térmica diferencial simultânea (TG-DTA), difratometria de raios X pelo método do pó, espectroscopia de absorção na região do infravermelho foram utilizadas para estudar os compostos derivados da purina. Sendo estes: aminofilina. teofilina, cafeína e ácido úrico. Os resultados forneceram informações com respeito à estabilidade térmica e decomposição térmica sobre esses compostos.

Synthesis and characterization of Fe(III)-doped ceramic membranes of titanium dioxide and its application in photoelectrocatalysis of a textile dye

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos da história térmica nas propriedades do polímero pet: um experimento para ensino de análise térmica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural transition on Pb1-xSrxTiO3 produced by chemical method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of high pressure in the Li2O-2SiO(2) crystallization

The aim of this work was to investigate the effect of previous treatments at high pressures on the crystallization kinetics of monolithic samples of a Li2O-2SiO(2) (LS2) glass. The glass transition temperature (T-g) and the temperature of the onset of crystallization (T-p) obtained by differential thermal analyses (DTA) were measured for LS2 glass samples submitted to isostatic pressures ranging from 2.5 to 7.7 GPa during 5 min at room temperature. The observed systematic changes in T-g and T-p were probably related to the cracks induced by high pressure inside the monolithic samples and in its surface. Away from the cracks, the nucleation density slightly decreased as a function of pressure but along the cracks, the nucleation density was significantly higher. (C) 2010 Elsevier B.V. All rights reserved.

Cure Kinetic of Castor Oil-Based Polyurethane

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dynamic mechanical properties for polyurethane elastomers applied in elastomeric mortar

Dynamic mechanical properties of a polyurethane (PU) elastomer and a mortar processed with the same elastomer (modified polytetramethylene ether glycol (PTMEG)) were studied. The results obtained showed that the liquid aromatic amine ETHACURE (R) 300, used as cure agent, can be used to substitute the aromatic amine MOCA (R), which is usually used as cure agent in high performance elastomers. The resulting mortar produced with ETHACURE (R) 300 presents similar dynamic-mechanical thermal properties when compared with MOCA (R). However, dynamic-mechanical thermal analysis studies showed that the mortar developed with ETHACURE (R) 300 presents some advantages such as the low values of tan d, indicating a good capacity of recovery of the strain after retreating an applied force. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Avaliação do comportamento termoanalítico e oxidativo do biodiesel de mamona

In this work biodiesel was gotten through the transesterification reaction using the oil of castor as source of triglycerides and using the methylic route for obtaining of esters. For the characterization of biodiesel and its mixtures with mineral diesel oil, physical chemical parameters and several analytical techniques had been used, as well as: gas chromatography (GC), nuclear magnetic resonance of proton (1H NMR), infrared spectroscopy (IR) and thermal analysis. The chromatography confirmed the complete reaction of esters in biodiesel presenting a 97,08% conversion. The 1H - NMR presented singlet in 3,6 ppm corresponding to the hydrogen of the group ester RCOO CH3. The infrared presented a strong band in 1741 cm-1 referring to stretching C=O of ester and an average band in 1175 cm-1 referring C O deformation. With the data of thermal analysis it was possible to observe the thermal and oxidative stability of the samples changing the atmospheres of synthetic air and nitrogen, where stages of the thermal decomposition had been verified and had been attributed to the volatilization and/or decomposition of the triacylglycerides. The thermal degradation of the samples was carried through 150 and 210°C during 1, 12, 24 and 48 hours and was observed change in the thermogravimetric profile, therefore an increase in the number of stages of the thermal decomposition also occurred indicating characteristic intermediate composites of polymerization, being this confirmed through the rheological study that presented brusque increase of viscosity. The kinetic study showed that the activation energy has the following order: biodiesel > mineral diesel oil > mixtures biodiesel/diesel