APPLICATION OF TIME-STRESS EQUIVALENCE TO NONLINEAR CREEP OF PHYSICALAGING POLY(METHYL METHACRYLATE)
The effects of physical aging and stress on creep of poly(methyl methacrylate) were investigated,and the time-aging time superposition principle (TASP) and the time-stress superposition principle (TSSP) were applied to construct a unified master creep curve.After annealing above glass transition temperature,the specimens were quenched and aged at aging temperature 50 ℃for different aging times,and then the short-term creep strains were measured under different stress levels at ambient temperature.The results show that the creep rate increases with stress,but decreases with aging time.It is also shown that the aging time shift factors vary with the stresses at which the shifts are applied.For linear viscoelastic material,the aging shift rate is independent on imposed stress,while for nonlinear viscoelastic material,the aging shift rate decreases with increasing stress.The unified master creep curve is constructed by shifting the creep curves horizontally along the logarithmic time axis to overlap each other.It is demonstrated that TSSE associated with TASE can be used to assess the long-term mechanical behaviors of physical aging polymers.
viscoelasticity physical aging shift factor
Rongguo Zhao Wenbo Luo Jianghua Tan Qifu Li Chaozhong Chen
College of Civil Engineering and Mechanics,Xiangtan University,Xiangtan,Hunan 411105,China Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education,Xiangtan University,Xiangtan Hunan 411105,China
国际会议
第二届国际非均质材料力学会议(The Second International Conference on Heterogeneous Material Mechanics)
安徽黄山
英文
1142-1145
2008-06-03（万方平台首次上网日期，不代表论文的发表时间）