Abstract The effect of monomer concentration on the adhesive strength of polytetrafluoroethylene (PTFE) films treated with atmospheric-pressure nonthermal plasma (NTP) graft polymerization is investigated. In this study, we use acrylic acid (CH2=CHCOOH) as the monomer, and two types of evaporation vessels (named vessel I and vessel II) are prepared to generate the monomer vapor. Vessel II consists of a pair of evaporation containers that have half the evaporation area of vessel I. The monomer concentration in the treatment chamber is adjusted by controlling the monomer temperature. After purging the chamber with Ar, a jet of NTP is applied to the PTFE film surface at an Ar flow rate of 40 L/min. The treated PTFE films are then adhered to stainless steel plates using double-sided tape, and 90° peeling tests are conducted. It is found that the peeling strength increases with decreasing monomer concentration. When the acrylic acid temperature in vessel II is set to 55 °C, the monomer concentration is estimated to be 980 ppm, and the highest peeling strength per unit width of 4.85 N/mm is obtained under this condition. Despite the same monomer temperature used (60 °C), the peeling strength of the PTFE films treated in vessel II is higher than that of films treated in vessel I. Additionally, smaller data variation is observed when vessel II is used. This result is due to the uniform distribution of monomer concentration achieved when vessel II is used to generate the monomer vapor. Furthermore, information regarding the chemical bonding and elemental composition of the untreated and treated films is obtained using X-ray photoelectron spectroscopy measurements and the graft-polymerized surface morphologies are studied using scanning electron microscopy.

中文翻译：

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单体浓度对常压非热等离子体接枝聚合处理的聚四氟乙烯薄膜粘合强度的影响

摘要 研究了单体浓度对常压非热等离子体(NTP)接枝聚合处理的聚四氟乙烯(PTFE)薄膜粘合强度的影响。在本研究中，我们使用丙烯酸（CH2=CHCOOH）作为单体，并准备了两种类型的蒸发容器（称为容器 I 和容器 II）来产生单体蒸汽。容器II由一对蒸发容器组成，其蒸发面积是容器I的一半。处理室中的单体浓度通过控制单体温度来调节。用 Ar 吹扫腔室后，以 40 L/min 的 Ar 流速将 NTP 射流施加到 PTFE 膜表面。然后使用双面胶带将处理过的 PTFE 薄膜粘附到不锈钢板上，并进行 90° 剥离测试。发现剥离强度随着单体浓度的降低而增加。当容器II中的丙烯酸温度设置为55°C时，单体浓度估计为980 ppm，并且在该条件下获得了4.85 N/mm的最高单位宽度剥离强度。尽管使用相同的单体温度 (60 °C)，但在容器 II 中处理的 PTFE 薄膜的剥离强度高于在容器 I 中处理的薄膜的剥离强度。此外，使用容器 II 时观察到的数据变化较小。这一结果是由于当容器 II 用于产生单体蒸汽时实现了单体浓度的均匀分布。此外，