聚苯乙烯海南自然气候暴露后的老化现象

AGING PHENOMENON OF POLYSTYRENE AFTER NATURE EXPOSURE IN HAINAN

采用直接气候暴露、玻璃板下暴露和百页窗下暴露三种自然老化方法研究了聚苯乙烯 (PS)外观、力学性能和熔体流动速率在海南自然老化过程中的变化,考察了光、热、氧、水对PS老化的影响。结果表明,PS在海南的自然老化以断链反应为主,分子量的下降与太阳辐照强度密切相关;老化过程中,由于试样温度变化所产生的内应力是影响PS力学性能的重要因素;水对PS的各项性能不产生大的影响。

Three nature aging tests under direct exposure, glass and shutter were used to study the appearance,mechanical properties and MFR of PS during the process of nature exposure in Hainan. The influences of daylight,heat,oxygen and water on the aging of PS were investigated. The results showed that the nature aging was mainly in the form of chain rupturing reaction, and the degradation of molecular weight was nearly relative with solar radiation intension. During aging,internal stress generated by the change of sample temperature was an important factor which affected mechanical properties of PS. Water had few effects on the properties of PS.