基于紫外⁃臭氧辐照的挤塑聚苯乙烯表面改性研究

Surface modification of extruded polystyrene based on ultraviolet⁃ozone irradiation

采用紫外-臭氧(UVO)辐照方式对挤塑聚苯乙烯保温板(XPSF)进行了表面改性,通过X射线光电子能谱仪(XPS)、接触角测量仪(CA)和扫描电子显微镜(SEM)对改性前后XPSF表面化学结构、润湿性能及表面形貌的变化规律进行了表征和测试。结果表明,随着UVO辐照时间的延长,XPSF表面含氧官能团数量逐渐增加,尤其在15 min时,XPSF表面的O/C值(O和C原子含量比值)由0.04增加至0.59;经UVO辐照30 min后,XPSF表面与水的接触角从未经处理的101.7°降至37.1°;UVO辐照前后XPSF表面形貌差异很小;随着放置时间的延长,XPSF表面氧含量逐渐降低,表面形成的含氧官能团消失,疏水性产生一定恢复;放置7 d时XPSF表面仍为氧化状态,接触角表现为亲水性;放置14 d时XPSF表面化学性质和润湿性已恢复至原始状态,但XPSF表面形貌并不会随放置时间的变化而改变。

The surface of extruded polystyrene insulation board(XPSF)was modified through ultraviolet-ozone(UVO)irradiation,and then its chemical structure,wettability and surface morphology were investigated using an X-ray photo-electron spectroscope,a contact angle meter,and a scanning electron microscopy.The results indicated that more oxy-gen-containing groups were produced on the XPSF surface with an increase in the UVO irradiation time.Especially after UVO irradiation for 15 min,the atomic ratio of O to C elements of the XPSF surface was increased from 0.04 to 0.59.The contact angle between XPSF and deionized water droplets decreased from 101.7°to 37.1°after UVO irradiation for 30 min.The XPSF surface showed an unchanged morphology after UVO exposure.The oxygen content of XPSF decreased gradually with an increase in standing time,suggesting that the oxygen-containing groups were lost from the surface of XPSF,thus recovering the hydrophobicity.After storage for 7 days,XPSF was still oxidized,resulting in a hydrophilic surface.Nevertheless,the wettability and chemical structure of XPSF was returned to its original state after storage for 14 days.However,the XPSF surface still exhibited an unchanged morphology.