有机玻璃在液体闪烁体环境中的老化研究

Studying on the Aging of PMMA in Liquid Scintillation Environment

为了研究有机玻璃在液体闪烁体环境中老化后力学性能的变化情况,开展了老化试验。将有机玻璃试样分别浸泡在50、60以及70℃液体闪烁体中进行人工加速老化处理,并对老化30、60、124、180 d以及未老化处理的试样进行了拉伸性能测试,获得了试样在三种温度液体闪烁体环境中老化后的力学性能随老化时间的变化规律,并分析了老化机理。利用阿累尼乌斯方程外推法对有机玻璃长期力学性能进行预测,推算出有机玻璃在20℃液体闪烁体环境中使用20 a后的拉伸强度下降了约10%。

The artificial accelerated aging test for polymethylmethacrylate （PMMA） was carried out for the purpose of studying the change of mechanical properties of PMMA aged in liquid scintillation. The PMMA specimens were respectively soaked in 50, 60 and 70 ℃ liquid scintillation and the tension tests were conducted before aging and after aging for 30, 60, 124 and 180 d. With the experimental data, the relation between the tensile strength and aging time at the three temperatures in the liquid scintillation was obtained and the aging mechanisms were analyzed. Finally the Arrhenius equation was extrapolated to predict that the tensile strength of PMMA would reduce by about 10% after aging at 20 ℃ in liquid scintillation for 20 years.