脉冲射频等离子体聚合沉积乙烯基乙酸

Deposition of vinyl acetic acid through the pulsed rf plasma polymerization

通过脉冲射频等离子体聚合方法获得乙烯基乙酸沉积薄膜 ,并用红外光谱、x射线光电子能谱、表面张力、微分扫描量热分析及扫描电子显微镜等测试方法研究聚合沉积薄膜的化学结构、表面物理形貌与脉冲放电条件的关系 .实验结果表明 ,采用脉冲放电 ,在脉冲占空比较低时 ,能够保留较多的完整的单体分子官能团 .如果脉冲占空比较高或是采用连续波放电时 ,聚合沉积薄膜的化学结构与单体相比有较大改变 .聚合沉积薄膜在放置一段时间后表面为规整的高度交联的网络状结构 .放电形式不同 ,结构有所区别 .因此可以根据实际需要 ,选择不同的放电参数 ,“保留”或“裁剪”特定单体分子官能团 。

In this paper, pulsed rf plasma polymerization using vinyl acetic acid was investigated to obtain plasma polymers with less cross-linked structure and high-degree retention of the starting monomer groups. The chemical structure and the surface morphology of the polymerized vinyl acetic acid were characterized by Fourier transform infrared (FTIR) spectroscopy, x-ray photoelectron spectroscope (XPS) and scanning electron microscope (SEM). The duty cycles were observed to be one of the key parameters to change the film structure. The FTIR results showed that more carboxylic groups could be 'retained' with the decrease of the duty cycles. The XPS results were consistent with the FTIR measurements. Surface energy measurements indicated that the plasma films were hydrophilic. So controlling the chemical composition with some special surface functional groups being 'retented' or 'tailored' was available by pulsed plasma technologies. Some regular graft 'lighting' network patterns were interestingly found in the plasma films kept at room temperature for some time by SEM. It was estimated that the plasma polymerization proceeded differently along the 'lighting' network and on the valley of the pattern. The details need to be further studied.