TA技术讲座热分析与流变原理及其应用讲义e.PDF

動態黏彈理論動態黏彈理論 動態黏彈理論動態黏彈理論 力的控制方式力的控制方式 力的控制方式力的控制方式 1. 定定值值控制控制 定定值值控制控制 TRANSIT TEST Constant Force 對時間掃描 對溫度掃描 對相對溼度掃描 Creep Recovery Experiment (Stress Control) Stress is applied to sample instantaneously, t1, and held constant for a specific period of time. The strain is monitored as a function of time (γ (t) or ε(t)). The stress is reduced to zero, t2, and the strain is monitored as a function of time (γ(t) or ε(t)). s s e r t S t1 t2 time Creep: Material Response Rubbery Plateau Region Transition Region Glassy Region Terminal Region log time Constant Strain 對時間掃描 對溫度掃描 對相對溼度掃描 Stress Relaxation Experiment (Strain Control) Response of Material Stress decreases with time starting at some high value and decreasing to zero. 0 tim e For small deformations (strains within the linear region) the ratio of stress to strain is a function of time only. This function is a material property known as the STRESS RELAXATION MODULUS, G(t) G(t) = σ(t)/γ Stress Relaxation: Material Response Glassy Region