Deposition of vinyl acetic acid through the pulsed rf plasma polymerization

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.