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 language | English |
|---|---|
| Pages (from-to) | 890-895 |
| Number of pages | 6 |
| Journal | Journal of Physics and Chemistry of Solids |
| Volume | 73 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 2012 Jul 1 |
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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 journal › Article
}
TY - JOUR
T1 - Polymorphic phase transition and thermal stability in squaric acid (H 2C 4O 4)
AU - Lee, Kwang Sei
AU - Kweon, Jin Jung
AU - Oh, In Hwan
AU - Lee, Cheol Eui
PY - 2012/7/1
Y1 - 2012/7/1
N2 - 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.
AB - 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.
KW - B: Crystal growth
KW - C: Differential scanning calorimetry (DSC)
KW - C: Thermogravimetric analysis (TGA)
KW - C: X-ray diffraction
KW - D: Phase transitions
UR - http://www.scopus.com/inward/record.url?scp=84862779689&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84862779689&partnerID=8YFLogxK
U2 - 10.1016/j.jpcs.2012.02.013
DO - 10.1016/j.jpcs.2012.02.013
M3 - Article
VL - 73
SP - 890
EP - 895
JO - Journal of Physics and Chemistry of Solids
JF - Journal of Physics and Chemistry of Solids
SN - 0022-3697
IS - 7
ER -