物理化学学报 >> 2005, Vol. 21 >> Issue (09): 988-992.doi: 10.3866/PKU.WHXB20050909

研究论文 上一篇    下一篇

聚羟基丁酸-戊酸的非等温热分解反应动力学

袁军; 邓明进; 艾军; 解孝林; 郑启新   

  1. 华中科技大学生命科学与技术学院, 武汉 430073; 武汉化工学院化工与制药学院, 武汉 430073; 华中科技大学化学系, 武汉 430073
  • 收稿日期:2005-01-06 修回日期:2005-03-14 发布日期:2005-09-15
  • 通讯作者: 袁军 E-mail:hatalent@yahoo.com.cn

Non-isothermal Decomposition Kinetics of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

YUAN Jun; DENG Ming-jin; AI Jun; XIE Xiao-lin; ZHENG Qi-xin   

  1. Department of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430073; Department of Chemical Technology and Pharmaceutics, Wuhan Institute of Chemical Technology, Wuhan 430073; Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430073
  • Received:2005-01-06 Revised:2005-03-14 Published:2005-09-15
  • Contact: YUAN Jun E-mail:hatalent@yahoo.com.cn

摘要: 用非等温TG-DTA技术, 在5.0、10.0、15.0和20.0 K•min-1线性升温条件下, 研究聚羟基丁酸-戊酸(PHBV)的热分解反应动力学. 结果表明, 分解过程分三个阶段:分解初期、分解中期和分解后期. 分解初期的机理函数为Avrami-Erofeev方程(n=1/2), 对应随机成核和随后生长机理, 表观活化能Ea(β→0)为69.44 kJ•mol-1, 指前因子A(β→0)为106.27 s-1;分解中期的机理函数为Avrami-Erofeev方程(n =2/5), 对应随机成核和随后生长机理, 表观活化能Ea(β→0)为117.64 kJ•mol-1, 指前因子A(β→0)为1011.48 s-1;分解后期的机理函数为Mampel Power法则(n=1/3), 对应机理为幂函数法则, 表观活化能Ea(β→0)为116.64 kJ•mol-1, 指前因子A(β→0)为108.68 s-1.

关键词: 聚羟基丁酸-戊酸, 非等温动力学, 分解机理, 双外推法

Abstract: The thermal decomposition kinetics of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV) has been investigated by means of non-isothermal TG-DTA with various heating rates of 5.0, 10.0, 15.0, and 20.0 K•min-1. The result shows that the decomposition process of PHBV is composed of three stages:initial stage, medium stage, and end stage. The most probable kinetic function of the initial stage is the Avrami-Erofeev equation with n=1/2, and the corresponding machanism is controlled by random nuclear producing and growing process. The apparent activation energy (Ea(β→0)) and the pre-exponential constant(A(β→0)) are 69.44 kJ•mol-1 and 106.27 s-1 respectively. The most probable kinetic function of the medium stage is the Avrami-Erofeev equation with n=2/5, and the corresponding machanism is the same with the previous stage. The apparent activation energy (Ea(β→0)) and the pre-exponential constant (A(β→0)) are 117.64 kJ•mol-1 and 1011.48 s-1 respectively. The most probable kinetic function of the end stage is the exponential function with n=1/3, and the corresponding mechanism follows Mampel Power theorem. The apparent activation energy(Ea(β→0)) and the pre-exponential constant (A(β→0)) are 116.64 kJ•mol-1 and 108.68 s-1 respectively.

Key words: Poly(3-hydroxybutyrate-co-3-hydroxyvalerate), Non-isothermal kinetics, Decomposition mechanism, Double extrapolation method