辉光放电等离子体用于聚丙烯薄膜表面处理

为研究用辉光放电等离子体处理后材料表面成分和分子结构的变化,用辉光等离子体处理聚丙烯(PP)薄膜,利用红外光谱和扫描电镜检测了材料表面微观结构的变化,并用国标规定的装置检测了它的击穿场强。实验证明,处理后的PP膜表面粗糙度增加,且引入了极性基团,微观结构产生了变化,但薄膜击穿强度没有发生明显变化。这为已经进行过很多的、关于等离子体表面处理对材料击穿场强的影响的研究提供了充足的实验证明,另也从微观角度为等离子体表面处理提供了较深入的理论支持。

Treatment of Polypropylene Film Using Plasma Produced by Glow Discharge

Different kinds of gas including O2, N2 and Ar were used to treat PP film in different treatment intensity, and the treated film were analyzed by IR and SEM determination. The experimental results show that the kind of gas is the most important factor affecting the result, and there exists an optimum point for the treatment intensity. Infrared spectra show that under appropriate treatment conditions, some polarity groups such as COOH and OH are produced on the surface of film. However, the energy spectrum reveals that the mole and weight percents of C, N and O on the surface change a little, indicating that the amounts of polarity groups are very small, leading to little improvement in the characteristics for bulk of film. The SEM photographs show that the corrosion on the film surface is very serious, the amorphous phases are removed, the crystal phases are exposed on the surface, and the corrosion is uniform on the surface. This phenomenon indicates an obvious coarsen effect, which may lead to more sufficient impregnating progress. In order to further study the experimental phenomenon, this paper analyzes the chemical and physical mechanisms of plasma surface treatment. The process of plasma treatment can produce free radicals, polarity groups and form cross linkage lays. These chemical reactions may change the structures of the film surface, and bring about the reduction of initial charge carrier and decrease of electron conductivity in the bulk, leading to increase of the breakdown voltage Vb of the film. Some parts of experimental results are consistent with those of theoretical analyses.