聚(乳酸-乙醇酸)共聚物(75/25)缩聚反应动力学研究

Study on Polycondensation Kinetics of Poly(lactide-co-glycolide) (75/25)

研究了常压或减压条件下,无催化剂时端羧基聚(乳酸-乙醇酸)共聚物(75/25)的缩聚反应动力学。结果表明:(1)在155℃、无催化剂、常压条件下,反应程度在1 5%～8 0%范围内,乳酸、乙醇酸直接缩聚反应符合1.31级反应,反应活化能E=5.15kJ/mol。其动力学方程式为:(;2)在125℃、无催化剂、0.01MPa减压条件下,反应程度在20%～80%范围内,乳酸、乙醇酸直接缩聚反应符合0.68级反应,反应活化能E=3.21 kJ/mol。其动力学方程式为:。

To study the polycondensation Kinetics of poly（lactide-co-glycolide）（75/25） without any catalyst. The results shows that the direct condensation polymerization of lactic acid and glycolic acid（75/25） proceeds as a 1.31 order reaction in the equation of-d[COOH]/dt = 3.23 × 10^-3 [COOH]^1.31 at 155℃ within the extent of 15% - 80% and the activation energy is E=5.15 kJ/mol without any catalyst. In the condition of vacuum at 0.01MPa, the polycondensation proceeds as a 0.68 order reaction in the equation of -d[COOH]/dt=2.81 × 10^-3[COOH]^0.68at 125℃ within the extent of 20% - 80% and the activation energy is E=3.21kJ/mol without any catalyst.