Acta Phys. -Chim. Sin. ›› 2005, Vol. 21 ›› Issue (11): 1307-1310.doi: 10.3866/PKU.WHXB20051123

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Studies on Glass Transition Temperature ofNl Chitosan

DONG Yan-ming; RUAN Yong-hong; ZHAO Ya-qing; BI Dan-xia; YANG Liu-lin; GE Qiang   

  1. State Key Laboratory of Physical Chemistry of Solid Surface, Departement of Materials Science and Engineering, Xiamen University, Xiamen 361005
  • Received:2005-04-04 Revised:2005-05-27 Published:2005-11-15
  • Contact: DONG Yan-ming

Abstract: The glass transition behaviors of N-alkyl chitosan were investigated by means of differential scanning calorimetry (DSC) and thermally stimulated current (TSC) spectroscopy. In DSC measurements, the second heating run was used to eliminate the effect of solvents and heat history on glass transition temperature (Tg), and also physical aging was used to improve the sensitivity of Tg measurements by enhancing the enthalpy endothermal peaks. The results of two techniques showed that the glass transition temperatures of three N-alkyl chitosans were all within 110~150 ℃. When the length of flexible side-alkyl groups was larger, the transition points shifted to lower temperature. But N-methyl chitosan is an exception, its Tg is slightly higher than chitosan because of the steric hindrance of side group.

Key words: Chitosan, N-alkyl chitosan, Glass transition temperature, Physical aging, DSC, TSC