RF-Ar等离子体对聚乙烯薄膜的表面改性

Surface Modification of Polyethylene Film by RF-Ar Plasma Treatment

采用射频辉光放电氩等离子体,在工作压力为20 Pa、功率为30W的条件下对低密度聚乙烯薄膜进行了不同时间的表面处理。借助静态接触角、X射线光电子能谱仪、原子力显微镜、差示扫描量热仪对薄膜改性前后的性能进行了表征及分析。研究结果表明:氩等离子体短时间(20 s)处理便可以有效改善薄膜表面的亲水性,处理时间大于20 s后接触角的变化并不明显;处理后的薄膜表面引入了大量的含氧及少量的含氮官能团;薄膜表面所形成的交联层阻挡了极性基团的翻转,有效延长了接触角的时效性;薄膜的表面形貌和结晶度发生了变化。

The surfaces of the low density polyethylene （LDPE） sheet were modified by RF argon glow discharge plasma. The impacts of the surface modification conditions, including the pressure, plasma power, and modification time, on the surface morphologies and properties of the LDPE films were studied. The surfaces of the LDPE films, before and after the plasma treatment, were characterized with X-ray photoelectron spectroscopy, atomic force microscopy, static con- tact angle measurement, and differential scanning calorimetry. The results show that the plasma treatment time significantly affects the surface micmstmctures and properties. For instance, the plasma treatment for 20 s markedly improves the wetta- bilty of the LDPE surface; but a treatment time longer than 20 s little influences the contact angle. We suggest that the ex- istence of a high density of oxygen-containing and a low density of nitrogen-containing functional groups in the surfaces of the plasma modified LDPE films, may account for the slow the aging evolution of the surface contact angle.