Abstract A systematic study using a central composite design of experiments (DoE) was performed on the oxygen plasma surface modifications of two different polymers—Pellethane 2363-55DE, which is a polyurethane, and vinyltrimethoxysilane-grafted ethylene-propylene (EPR-g-VTMS), a cross-linked ethylene-propylene rubber. The impacts of four parameters—gas pressure, generator power, treatment duration, and process temperature—were assessed, with static contact angles and calculated surface free energies (SFEs) as the main responses in the DoE. The plasma effects on the surface roughness and chemistry were determined using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Through the sufficiently accurate DoE model evaluation, oxygen gas pressure was established as the most impactful factor, with the surface energy and polarity rising with falling oxygen pressure. Both polymers, though different in composition, exhibited similar modification trends in surface energy rise in the studied system. The SEM images showed a rougher surface topography after low pressure plasma treatments. XPS and subsequent multivariate data analysis of the spectra established that higher oxidized species were formed with plasma treatments at low oxygen pressures of 0.2 mbar.

中文翻译：

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聚合物薄膜的氧等离子体表面处理——Pellethane 55DE 和 EPR-g-VTMS

摘要 使用中心复合实验设计 (DoE) 对两种不同聚合物的氧等离子体表面改性进行了系统研究 - Pellethane 2363-55DE，这是一种聚氨酯和乙烯基三甲氧基硅烷接枝的乙丙烯 (EPR-g-VTMS )，一种交联的乙丙橡胶。评估了四个参数——气体压力、发电机功率、处理持续时间和工艺温度——的影响，其中静态接触角和计算出的表面自由能 (SFE) 作为 DoE 中的主要响应。使用扫描电子显微镜 (SEM) 和 X 射线光电子能谱 (XPS) 确定等离子体对表面粗糙度和化学的影响。通过足够准确的DoE模型评估，确定氧气压力为最影响因素，表面能和极性随着氧气压力的下降而上升。两种聚合物虽然组成不同，但在所研究的系统中表现出相似的表面能升高的改性趋势。SEM 图像显示低压等离子体处理后的表面形貌更粗糙。XPS 和随后的光谱多变量数据分析表明，在 0.2 毫巴的低氧压力下进行等离子体处理会形成更高的氧化物质。