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<p>This study examines the thermal decomposition behavior of Hymenolobium excelsum Duke and Cordia alliodora Ruiz Pav using differential scanning calorimetry (DSC). Samples were extracted from logs with a 35&#xa0;cm thickness at the diameter at breast height (DBH). Species identification was conducted using optical microscopy. The DSC experiments were carried out under both air and argon atmospheres at a heating rate of 10&#xa0;°C/min. The thermal profiles of both species revealed an endothermic peak, indicating moisture loss along with the volatilization of extractives and mineral content in the range of room temperature to 250&#xa0;°C. Multiple exothermic peaks corresponding to the sequential degradation of hemicelluloses, cellulose, and lignin were observed at elevated temperatures. Characteristic peak temperatures and enthalpies were determined for each degradation stage. A kinetic analysis employing 25 models was performed using the modified Freeman-Carroll and Achar methods, in conjunction with the Arrhenius equation, to evaluate activation energies and reaction orders. The Ginstling-Brounshtein diffusion mechanism (D5) provided the best description of the endothermic event, whereas the polymer degradation phases exhibited competitive behaviors between the Avrami-Erofeev mechanism and an interface-controlled reaction. FTIR-ATR spectroscopy revealed two prominent absorption bands around 1000&#xa0;cm<sup>−1</sup> and 3500&#xa0;cm<sup>−1</sup>, corresponding to symmetric C–O–C and O–H stretching vibrations, respectively.</p>

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Insights into the thermal stability properties of two hardwoods from the Amazon rainforest

  • 期刊论文

  • 发表日期：

    2025年2月27日

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  • L. de Souza-Cavalcante,
  • F. Guerrero,
  • J. Anglada-Rivera,
  • Y. Leyet,
  • F. M. A. da Silva,
  • G. Q. Ramos,
  • R. Matos,
  • H. D. da Fonseca Filho

摘要

This study examines the thermal decomposition behavior of Hymenolobium excelsum Duke and Cordia alliodora Ruiz Pav using differential scanning calorimetry (DSC). Samples were extracted from logs with a 35 cm thickness at the diameter at breast height (DBH). Species identification was conducted using optical microscopy. The DSC experiments were carried out under both air and argon atmospheres at a heating rate of 10 °C/min. The thermal profiles of both species revealed an endothermic peak, indicating moisture loss along with the volatilization of extractives and mineral content in the range of room temperature to 250 °C. Multiple exothermic peaks corresponding to the sequential degradation of hemicelluloses, cellulose, and lignin were observed at elevated temperatures. Characteristic peak temperatures and enthalpies were determined for each degradation stage. A kinetic analysis employing 25 models was performed using the modified Freeman-Carroll and Achar methods, in conjunction with the Arrhenius equation, to evaluate activation energies and reaction orders. The Ginstling-Brounshtein diffusion mechanism (D5) provided the best description of the endothermic event, whereas the polymer degradation phases exhibited competitive behaviors between the Avrami-Erofeev mechanism and an interface-controlled reaction. FTIR-ATR spectroscopy revealed two prominent absorption bands around 1000 cm−1 and 3500 cm−1, corresponding to symmetric C–O–C and O–H stretching vibrations, respectively.