PMMA压痕回复的二阶反应动力学方法分析

Second-Order Kinetics of Indentation Recovery in Polymethyl Methacrylate

通过原子力显微镜结合纳米压痕表征了聚甲基丙烯酸甲酯(PMMA)表面压痕的深度回复,考察了温度对压痕回复速率的影响。结果表明,初期压痕深度迅速回复,经过3 h左右压痕深度不再发生变化。随着实验温度的升高,压痕残余深度迅速降低,20℃时压痕残余深度约为120 nm,50℃时压痕残余深度降低到约10nm。采用二阶反应动力学方法对粘弹性压痕回复进行了分析,结果表明,该方法能够有效地预测压痕的粘弹性深度回复。

The temperature-dependent indent recovery of polymethyl methacrylate （PMMA） was measured by atomic force microscopy （AFM）. The recovery rate decreases significantly along with the passage of the time. With the annealing temperature increasing, the permanent deformation reduces from 120nm of 20 ℃ to 10nm of 50 ℃, and the recovery rate increases greatly. The viscoelastic indent recovery was studied by second-order kinetics method. The variation of the viscoelastic deformation with time was found to follow second order kinetics for the indentation recovery. It may be a method for the prediction of deformation recovery on the polymer surface.