聚亚苯基苯并二噁唑在双螺杆挤出机中的后聚合反应动力学

Post-Polymerization Kinetics of Poly(p-phenylenebenzobisoxazole) in Twin Screw Extruder

通过正交分析的实验方法,考察了在螺杆挤出机中反应温度、螺杆转速、反应时间对聚亚苯基苯并二噁唑(PBO)后聚合反应速率的影响。结果显示:在3个影响因素中,温度影响最大,其次是反应时间,转速影响最小。并研究了PBO后聚合反应动力学,发现PBO双螺杆挤出机后聚合反应为扩散速率控制过程,其动力学符合不可逆二级化学反应机理。随着缩聚温度的增加,反应速率增加,反应温度从160℃提高到190℃,反应速率常数可提高4倍,测得反应活化能为84.4 kJ/mol。

The key parameters of processing temperature, reaction time and screw speed for poly（p-phenylenebenzoxisoxazole） （PBO） were investigated by orthogonal analysis methods. The processing temperature is the most important, then is the reaction time, and the screw rotation speed is the least in this extruding polymeration process. The post-polymerization kinetics was studied. The polycondensation is controlled by diffusion rate and the kinetics is accorded with the irreversible reaction of the second order. When the extrude temperature heats up from 160 ℃ to 190 ℃, the rate constants of reaction increase by 4 folds. The activation energy is 84.4 kJ/mol.