Abstract:

The decomposition reaction and mechanism of abietic acid with the purity 99.32% was tested by thermogravimetric analysis (TG),differential scanning calorimetry (DSC) and thermogravimetric analyzer coupled to a quadrupole mass spectrometer (TG-MS). The thermal decomposition activation energy of abietic acid at 20%(TG), 40%(TG), 60%(TG) were 12.76, 12.96, 11.81 kJ·mol^-1, respectively. The results of TG-MS showed that there are micromolecules, whose m/z are between 40 to 90 when decomposed after 362.2 ℃, which proved that the decomposition process of abietic acid is first off isopropyl, carboxyl, and then open-ring. The fusion heat, heat of gasification, heat capacity of solid state, liquid state and phase change form solid to liquid were 49.3 J·g^-1, 2 096.4 J·g^-1, 1.469 J·g^-1K^-1, 1.163 J·g^-1K^-1 and 4.769 J·g^-1K^-1, respectively.

Key words: abietic acid, thermal analysis, thermal decomposition kinetics, heat capacity