Polymorphic phase transition and thermal stability in squaric acid (H 2C 4O 4)

Kwang Sei Lee, Jin Jung Kweon, In Hwan Oh, Cheol Eui Lee

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Phase transformations in squaric acid (H 2C 4O 4) have been investigated by thermogravimetry and differential scanning calorimetry with different heating rates β. The mass loss in TG apparently begins at onset temperatures T di=245±5°C (β=5°C min -1), 262±5°C (β=10°C min -1), and 275±5°C (β=20°C min -1). A polymorphic phase transition was recognized as a weak endothermic peak in DSC around 101°C (T c +). Further heating with β=10°C min -1 in DSC revealed deviation of the baseline around 310°C (T i), and a large unusual exothermic peak around 355°C (T p), which are interpreted as an onset and a peak temperature of thermal decomposition, respectively. The activation energy of the thermal decomposition was obtained by employing relevant models. Thermal decomposition was recognized as a carbonization process, resulting in amorphous carbon.

Original languageEnglish
Pages (from-to)890-895
Number of pages6
JournalJournal of Physics and Chemistry of Solids
Volume73
Issue number7
DOIs
Publication statusPublished - 2012 Jul 1

Fingerprint

thermal decomposition
Pyrolysis
Thermodynamic stability
thermal stability
Phase transitions
acids
Acids
heating
carbonization
Amorphous carbon
Carbonization
thermogravimetry
Heating rate
phase transformations
Thermogravimetric analysis
Differential scanning calorimetry
heat measurement
Activation energy
activation energy
deviation

Keywords

  • B: Crystal growth
  • C: Differential scanning calorimetry (DSC)
  • C: Thermogravimetric analysis (TGA)
  • C: X-ray diffraction
  • D: Phase transitions

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Chemistry(all)
  • Materials Science(all)

Cite this

Polymorphic phase transition and thermal stability in squaric acid (H 2C 4O 4). / Lee, Kwang Sei; Kweon, Jin Jung; Oh, In Hwan; Lee, Cheol Eui.

In: Journal of Physics and Chemistry of Solids, Vol. 73, No. 7, 01.07.2012, p. 890-895.

Research output: Contribution to journalArticle

Lee, Kwang Sei ; Kweon, Jin Jung ; Oh, In Hwan ; Lee, Cheol Eui. / Polymorphic phase transition and thermal stability in squaric acid (H 2C 4O 4). In: Journal of Physics and Chemistry of Solids. 2012 ; Vol. 73, No. 7. pp. 890-895.
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