Evidence of non-Arrhenius behaviour from laboratory aging and 24-year field aging of polychloroprene rubber materials
Evidence of non-Arrhenius behaviour from laboratory aging and 24-year field aging of polychloroprene rubber materials
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DOI：
10.1016/j.polymdegradstab.2004.06.010
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发表时间：
2005-01-01
影响因子：
5.9
通讯作者：
Derzon, DK
中科院分区：
文献类型：
--
作者：
Gillen, KT;Bernstein, R;Derzon, DK
对商用氯丁橡胶Rabie护套材料进行了110℃至80℃的高温烘箱老化暴露，通过跟踪极限拉伸伸长率来监测每个温度下随时间变化的降解情况。通过在最低实验温度(80℃)下对结果进行时间-温度叠加。首先导出经验位移因子，然后用传统的Arrhenius方法进行分析，最后用导出的96kJ/mol的活化能E-a外推，以便在25℃下进行预测。为了测试Arrhenius外推背后的恒定E-a假设，我们在25摄氏度到95摄氏度的六个温度下进行了氧气消耗测量，发现了E-a缓慢下降的证据，从80摄氏度以上的96kJ/冷却到80摄氏度以下的82kJ/mol的平均值。这一曲率预测了室温寿命将减少50%，并表明随着室温的临近，某些更高的E-a降解过程变得滞后重要。对二氧化碳产生率的分析表明，随着温度的降低，二氧化碳相对于消耗的氧气变得不那么重要，这与上述建议是一致的。进一步明显：对于类似的E下降(从70℃以上的89kJ/mol到70℃以下的71kJ/mol)，来自与25年前另一种氯丁橡胶电缆护套材料的加速老化伸长率数据的比较，以及最近在类似于24摄氏度老化24年的样品上的伸长率结果。爱思唯尔有限公司出版。
High-temperature oven aging exposures from 110 C to 80 C have been conducted on a commercial chloroprene rublter rabie jacketing material where the time-dependent degradation at each temperature is monitored by following the ultimate tensile elongation. By time-temperature superposing the results at the lowest experimental temperature (80degreesC). empirical shift factors are first derived and then analysed using the conventional Arrhenius approach and finally extrapolated using the derived activation energy E-a of 96kJ/mol in order to make predictions at 25degreesC. To test the constant E-a assumption underlying the Arrhenius extrapolation, we conducted oxygen consumption measurements at six temperatures ranging from 25degreesC to 95degreesC and found evidence for a slow drop in E-a from similar to96 kJ/cool above 80degreesC to an average value of similar to82 kJ/mol below 80degreesC. This curvature predicts a 50% reduction in room temperature lifetime and suggests that certain higher E-a degradation proca.ses become lag important as room temperature is approached. Analyses of the production rates for CO2 show that CO2 becomes less important relative to the oxygen consumed as the temperature is lowered, evidence in accord with the above suggestion. Further evident: for a similar drop in E, (from 89 kJ/mol above 70 C to 71 kJ/mol below 70 C) comes from comparisons of accelerated aging elongation data taken similar to25 years ago on another chloroprene rubber cable jacketing material with recent elongation results taken on samples that have aged for similar to24 years at similar to24degreesC. Published by Elsevier Ltd.