中文摘要：

选择吐鲁番和若羌2个典型干热自然环境开展为期1年的自然大气暴露试验，研究了聚苯乙烯（PS）在干热自然环境下分子结构的变化，并对老化后的PS进行傅里叶变换红外光谱、凝胶渗透色谱和差示扫描量热分析。结果表明，PS发生光氧化反应并发生分子链断裂，导致其相对分子质量降低、相对分子质量分布变宽和玻璃化转变温度降低。

英文摘要：

In order to study the molecular structure changes of polystyrene in natural dry-hot environment, outdoor exposure test was performed in Turpan and Ruoqiang for one year, and FTIR, GPC, and DSC analysis were performed thereafter. It showed that photo-degradation and chain scission occurred, resulting in the decreasing of molecular weight, broadening of molecular weight distribution, and lowering of glass transition temperature.