目的 了解干热环境条件对聚苯乙烯表面结构及性能的影响。 方法 在吐鲁番和敦煌大气环境中对聚苯乙烯进行 1 年自然曝晒试验,研究聚苯乙烯表面黄色指数、微观结构随暴露时间的变化规律。结果 在干热大气环境中,随暴露时间延长,聚苯乙烯表面黄色指数增加,出现裂纹,老化过程中有 C O和 O—C O 基团生成。 结论 聚苯乙烯在干热大气环境中的老化主要由光氧化引起的链断裂和羰基增加造成。

Objective To find out the effects of dry-heat environment on the surface structure of polystyrene. Methods The exposure test of polystyrene( PS) was carried out for one year in Tulufan and Dunhuang. The changes of surface morphology and chemical structures were studied by spectrophotometry, fourier transform infrared ( FTIR) spectroscopy and X-ray photoelectron spectroscopy. Results Cracks on polystyrene surface were observed and yellow index was increased with prolonging exposure time.Organo-functional group C O and O—C O were found during the aging period. Conclusion Photodegradation of polystyrene in dry-heat environment was induced by chain break and increase in carbonyl group.