高聚物长时标力学行为的预测 (Ⅱ)物理老化对环氧树脂长时标力学行为和使用寿命的依赖性

Study on the Prediction of Long-Term Mecbanical Behavior and Lifetime for Polymere (2) Dependence of Aging Time on the Loug-Term Mechanical Behavior and Lifetime for Cross-Linked Epoxies

用统计力学和老化反应动力学相结合的方法,求得了高聚物应力松弛模量和蠕变柔量同老化时间(t_q)、松弛时间和推迟时间系数(α和β)和特征时间(t_0)之间的定量关系式,分析了环氧树脂的应力松弛和蠕变实验数据,得到了它们的松弛时间和推迟时间系数(α和β)和特征时间(t_0)值及t_0对t_a的依赖性,建立了统一组合直线,分析了老化时间对长时标力学行为(尺寸稳定和负荷可载性)的依赖性。通过应力松弛和蠕变性能测试,成功地把无外力作用下物理老化、化学老化同有力作用下物理化学老化结合起来。并建议一种从主组合直线外推来预测环氧树脂长时标力学行为方法。

In this paper a universal creep and stress relaxation function was derivedtheoretically by the combination of the kinetics of aging in free and deformed state. Theyare successful in relating the compliance and modulus to the aging time,the ratio of relaxa-tion times in free and deformed state,and the coefficient of relaxation and the time ofdeformation.Basing on these relations the effect of aging time on the dimensionalstability,the responsibility for load and the lifetimc for crosslinked epoxies were studied. Anew method for determining the long-term mechanical behavior and life-time from themaster lines of creep and stress relaxation was proposed.