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Journal of Thermal Analysis and Calorimetry
Authors: Jorge López-Beceiro, Ramón Artiaga, Carlos Gracia, Javier Tarrío-Saavedra, Salvador Naya, and José Luis Mier

(PDSC) has the additional advantage of reducing evaporation from the sample and it gets results in less time than conventional DSC. The OOT method (ASTM E2009) [ 17 ] measures the degree of oxidative stability of the substance at a given heating rate

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Journal of Thermal Analysis and Calorimetry
Authors: R. A. Candeia, F. S. M. Sinfrônio, T. C. Bicudo, N. Queiroz, A. K. D. Barros Filho, L. E. B. Soledade, I. M. G. Santos, A. L. Souza, and A. G. Souza

viscosities, UV–Vis absorption spectroscopy and PDSC techniques. Experimental Fatty acid methyl and ethyl esters (FAME and FAEE, respectively) were obtained by base-catalyzed transesterification of soybean oil [ 29 , 30 ]. The

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Journal of Thermal Analysis and Calorimetry
Authors: Jorge López-Beceiro, Carlos Gracia-Fernández, Javier Tarrío-Saavedra, Silvia Gómez-Barreiro, and Ramón Artiaga

electrically heated diamond anvil cell (DAC) at high pressures [ 15 ]. The aim of this study is to investigate by pressure differential scanning calorimetry (PDSC) the dependence of the thermal behavior on pressure in the range from 1 to 70 bar

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Journal of Thermal Analysis and Calorimetry
Authors: N. Santos, J. Santos, F. Sinfrônio, T. Bicudo, I. Santos, N. Antoniosi Filho, V. Fernandes, and A. Souza

Abstract  

The babassu (Orbignya Phalerata Mart.) biodiesel has lauric esters as main constituents, resulting in high oxidative stability and low cloud and freezing points. In order to reduce these side effects, the saturated ethyl esters content was reduced by means of winterization process. The TMDSC and PDSC techniques were used to verify the thermal and oxidative stabilities of the ethyl babassu biodiesel. During the heating stage, the winterized solid phase of ethyl esters presented an endothermic transition associated to the solidification process. This behavior was not observed for the liquid winterized FAEE, confirming the efficiency of the winterization process.

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Journal of Thermal Analysis and Calorimetry
Authors: C. Gracia-Fernández, J. Tarrío-Saavedra, J. López-Beceiro, S. Gómez-Barreiro, S. Naya, and R. Artiaga

effect of pressure on reactant volatilization has been investigated by pressure differential scanning calorimetry (PDSC) [ 9 – 11 ]. Hermetically sealed pans are usually adequate to contain the small amount of reaction products associated with cure. Some

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Abstract  

Biodiesel is a non-toxic biodegradable fuel that consists of alkyl esters produced from renewable sources, vegetal oils and animal fats, and low molecular mass alcohols, and it is a potential substitute for petroleum-derived diesel. Depending on the raw materials used, the amount of unsaturated fatty acids can vary in the biodiesel composition. Those substances are widely susceptible to oxidation processes, yielding polymeric compounds, which are harmful to the engines. Based on such difficulty, this work aims to evaluate the antioxidant activity of cashew nut shell liquid (cardanol), as additive for cotton biodiesel. The oxidative stability was investigated by the pressure differential scanning calorimetry (PDSC) and UV/Vis spectrophotometer techniques. The evaluated samples were: as-synthesized biodiesel — Bio T0, additivated and heated biodiesel — Bio A (800 ppm L−1 of hydrogenated cardanol, 150°C for 1 h), and a heated biodiesel — Bio B (150°C, 1 h). The oxidative induction time (OIT) analyses were carried out employing the constant volume operation mode (203 psi oxygen) at isothermal temperatures of 80, 85, 90, 100°C. The high pressure OIT (HPOIT) were: 7.6, 15.7, 22.7, 64.6, 124.0 min for Bio T0; 41.5, 77.0, 98.6, 106.6, 171.9 min for Bio A and 1.7, 8.2, 14.8, 28.3, 56.3 min for Bio B. The activation energy (E) values for oxidative processes were 150.0±1.6 (Bio T0), 583.8±1.5 (Bio A) and 140.6±0.1 kJ mol−1(Bio B). For all samples, the intensities of the band around 230 nm were proportional to the inverse of E, indicating small formation of hyper conjugated compounds. As observed, cardanol has improved approximately four times the cotton biodiesel oxidative stability, even after the heating process.

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Journal of Thermal Analysis and Calorimetry
Authors: Luzia Patricia Fernandes Carvalho Galvão, Anne Gabriella Dias Santos, Amanda Duarte Gondim, Marcela Nascimento Barbosa, Antonio Souza Araujo, Luiz Di Souza, and Valter José Fernandes Junior

controlled conditions and may be evaluated by thermal analysis techniques by using pressure differential scanning calorimetry (P-DSC) [ 14 , 15 ]. The purpose of this study was to evaluate the thermal and oxidative stability of the cotton and

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Biodiesel from soybean oil, castor oil and their blends

Oxidative stability by PDSC and rancimat

Journal of Thermal Analysis and Calorimetry
Authors: M. B. Dantas, A. R. Albuquerque, L. E. B. Soledade, N. Queiroz, A. S. Maia, I. M. G. Santos, A. L. Souza, E. H. S. Cavalcanti, A. K. Barro, and A. G. Souza

stability there are the Rancimat methods (EN 14112, 110 °C [ 8 ]) and AOCS (Cd 12b-92, [ 9 ]). The oxidative stability for fatty acid esters may also be accompanied successfully by pressure differential scanning calorimetry (PDSC) [ 3 , 10 ]. In the

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fast and accurate analytical processes and techniques which highlights P-DSC and MT-DSC studies for oxidative stability [ 1 ] and cold flow [ 2 – 4 ]. A preliminary observation of the fatty acid composition of the raw material allows the prediction of

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systems TNT/TNAZ/DNTF and TNAZ/DNTF/RDX have been determined, as similar to the binary systems with volatilizable materials in previous study [ 10 ], under pressure ambience by High Pressure Differential Scanning Calorimetry (PDSC) in this study. The

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