Acta Phys. -Chim. Sin. ›› 2005, Vol. 21 ›› Issue (09): 988-992.doi: 10.3866/PKU.WHXB20050909

• ARTICLE • Previous Articles     Next Articles

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

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