This study aimed to evaluate the combined effects of sulfonation, non-thermal oxygen plasma and silane on the shear bond strength (SBS) of PEEK to resin materials. Two hundred and eighty specimens were randomly divided into four groups: (A) untreated; (B) sulfonation for 60 s; (C) oxygen plasma for 20 min; (D) sulfonation for 60 s and oxygen plasma for 20 min. According to the instructions, 120 samples (N = 30) were coated with silane, adhesive, and resin composites. Each group of bonding specimens was divided into two subgroups (n = 15) to measure immediate and post-aging SBS. The surface morphology and the interface between the samples and adhesive were analyzed through SEM. Physicochemical characteristics of the surface and mechanical properties were determined through XPS, FTIR, light interferometry, contact angle measurement, and three-point bending tests. Sulfonation produced a porous layer of approximately 20 µm thickness on the surface, and the oxygen plasma increased the O/C ratio and oxygen-containing groups of the sample surface. After coating with silane, the SBS values of sulfonated PEEK and plasma-treated PEEK increased (9.96 and 10.72 MPa, respectively), and dual-modified PEEK exhibited the highest SBS value (20.99 MPa), which was significantly higher than that of blank group (p > 0.01). After 10,000 thermal cycles, the dual-modified PEEK still displayed a favorable SBS (18.68 MPa). Sulfonation strengthened the mechanical interlocking between PEEK and the resin while oxygen plasma established a chemical bonding between silane and PEEK. This dual modification of the surface microstructure and chemical state synergistically improved the bond strength of PEEK to resin and resulted in considerable long-term effects.

中文翻译：

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磺化、氧等离子体和硅烷联合改性对PEEK与树脂结合强度的影响

本研究旨在评估磺化、低温氧等离子体和硅烷对 PEEK 与树脂材料的剪切粘合强度 (SBS) 的综合影响。 280个标本被随机分为四组：（A）未处理； (B)磺化60s； (C) 氧等离子体20分钟； (D) 磺化 60 秒，氧等离子体 20 分钟。根据说明，120 个样品（N = 30）涂有硅烷、粘合剂和树脂复合材料。每组粘合样本均分为两个亚组 (n = 15)，以测量即时和老化后的 SBS。通过SEM分析表面形貌以及样品与粘合剂之间的界面。通过XPS、FTIR、光干涉测量、接触角测量和三点弯曲测试确定表面的物理化学特性和机械性能。磺化在表面产生约20μm厚的多孔层，氧等离子体增加了样品表面的O/C比和含氧基团。硅烷涂覆后，磺化PEEK和等离子体处理PEEK的SBS值均增加（分别为9.96和10.72 MPa），双改性PEEK表现出最高的SBS值（20.99 MPa），显着高于空白组（p > 0.01）。经过 10,000 次热循环后，双重改性 PEEK 仍然表现出良好的 SBS (18.68 MPa)。磺化增强了 PEEK 和树脂之间的机械联锁，而氧等离子体则在硅烷和 PEEK 之间建立了化学键。这种表面微观结构和化学状态的双重改性协同提高了 PEEK 与树脂的粘合强度，并产生了相当大的长期效果。