Hukins D W L, Mahomed A, Kukureka S N
School of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Med Eng Phys. 2008 Dec;30(10):1270-4. doi: 10.1016/j.medengphy.2008.06.001. Epub 2008 Aug 9.
Elevated temperature is frequently used to accelerate the aging process in polymers that are associated with medical devices and other applications. A common approach is to assume that the rate of aging is increased by a factor of 2(DeltaT/10), where DeltaT is the temperature increase. This result is a mathematical expression of the empirical observation that increasing the temperature by about 10 degrees C roughly doubles the rate of many polymer reactions. It is equivalent to assuming that the aging process is a first order chemical reaction with an activation energy of 10R/log(e)2, where R is the universal gas constant. A better approach would be to determine the activation energy for the process being considered but this is not always practicable. The simple approach does not depend on the temperature increase, provided that it is not so great that it initiates any physical or chemical process that is unlikely to be involved in normal aging. If a temperature increment theta were to increase a given polymer reaction rate n times, then an elevated temperature would increase the rate of aging by a factor of n(DeltaT/theta).
升高温度常用于加速与医疗设备及其他应用相关的聚合物的老化过程。一种常见的方法是假定老化速率提高2(ΔT/10)倍，其中ΔT是温度升高值。这一结果是对经验观察的数学表达，即温度升高约10℃大致会使许多聚合物反应速率翻倍。这等同于假定老化过程是一个活化能为10R/log(e)2的一级化学反应，其中R是通用气体常数。更好的方法是确定所考虑过程的活化能，但这并不总是可行的。只要温度升高幅度不至于引发任何不太可能在正常老化中出现的物理或化学过程，这种简单方法就不依赖于温度升高值。如果温度增量θ使给定聚合物反应速率提高n倍，那么升高的温度会使老化速率提高n(ΔT/θ)倍。
