Abstract Microcrystalline cellulose (MCC) and sawdust (SD) green fillers have great potential to act as moisture reservoirs and reactive fillers. In the present study, a one-component moisture curable polyurethane (PU) adhesive was reinforced with MCC and SD fillers. The durability of aluminum/steel joints produced using unreinforced and reinforced PU adhesives was studied using dynamic mechanical analysis (DMA), fatigue, and hygrothermal aging experiments. Lap-shear tests were conducted to evaluate the effects of aging on joints strength. Fourier-transform infrared spectroscopy (FTIR) experiments were performed on adhesive joints after hygrothermal aging to understand the changes in chemical structure due to aging, and the influence of cellulosic fillers on the aging phenomena. DMA results showed that the glass transition temperature of the reinforced PU was similar to that of the unreinforced PU. Fatigue performance of MCC and SD reinforced PU adhesive joints was found to be better than unreinforced PU joints. Further, MCC reinforced PU adhesive joints were found to be more resistant to hygrothermal aging than SD reinforced and unreinforced PU joints. Overall, MCC reinforced PU adhesive joints exhibited good fatigue and superior long-term properties.

中文翻译：

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纤维素颗粒增强的单组分湿固化聚氨酯粘合剂接头的湿热老化、疲劳和动态力学行为

摘要 微晶纤维素 (MCC) 和锯末 (SD) 绿色填料具有作为水分储存器和反应性填料的巨大潜力。在本研究中，一种单组分湿固化聚氨酯 (PU) 粘合剂用 MCC 和 SD 填料增强。使用动态力学分析 (DMA)、疲劳和湿热老化实验研究了使用未增强和增强 PU 粘合剂生产的铝/钢接头的耐久性。进行搭接剪切试验以评估老化对接头强度的影响。对湿热老化后的胶接缝进行傅里叶变换红外光谱 (FTIR) 实验，以了解老化引起的化学结构变化，以及纤维素填料对老化现象的影响。DMA 结果表明，增强 PU 的玻璃化转变温度与未增强 PU 的玻璃化转变温度相似。发现 MCC 和 SD 增强 PU 粘合接头的疲劳性能优于未增强 PU 接头。此外，发现 MCC 增强的 PU 粘合接头比 SD 增强和未增强的 PU 接头更耐湿热老化。总体而言，MCC 增强 PU 粘合接头表现出良好的疲劳和优异的长期性能。