Characterisation of moisture diffusion and strength degradation in an epoxy-based structural adhesive considering a post-curing process
Characterisation of moisture diffusion and strength degradation in an epoxy-based structural adhesive considering a post-curing process
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考虑后固化过程的环氧结构粘合剂中水分扩散和强度下降的表征
DOI：
10.1080/01694243.2018.1436876
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发表时间：
2018
影响因子：
2.3
通讯作者：
Yu Ye
中科院分区：
文献类型：
--
作者：
Han Xiao;Jin Yong;Zhang Wei;Hou Wenbin;Yu Ye
胶接技术在航空航天、车辆、土木工程等工业领域得到了广泛的应用，而粘结结构被设计成在复杂的使用条件下令人满意地工作。本文提出了一个实验洞察的水分扩散过程中Araldite 2015胶粘剂考虑的影响，在高温下的后固化过程。哑铃型胶粘剂试样的固化过程采用塑料模具，并引入蒸馏水和盐水模拟恶劣的浸泡环境。对未老化和老化的本体胶粘剂在一定时间的浸泡后进行准静态测试，以揭示机械性能的变化。在浸泡过程中，以不同的时间间隔对试样的重量和厚度进行测量。结果表明，散装粘合剂的强度显着下降，由于水的存在下，在这两个浸泡条件下，其中较高的水分含量导致更大的强度退化，无论固化和老化条件下应用。此外，蒸馏水环境导致显着更高的饱和度含量和吸湿膨胀相比，盐水。然而，在盐水中的水扩散和吸湿膨胀过程的速率被检测到远高于在蒸馏水中的。值得注意的是，观察到后固化粘合剂的湿饱和含量和溶胀膨胀略有增加，而吸湿溶胀系数在所研究的所有样品组中没有显示出差异。扫描电子显微镜观察进一步揭示了从未老化到饱和样品的微观形貌的转变。
Abstract Adhesive bonding techniques have been widely used in many industrial fields, such as aerospace, vehicle and civil engineering, etc., while the bonded structures are designed to perform satisfactorily under complex service conditions. This paper presented an experimental insight into the moisture diffusion process in Araldite 2015 adhesive considering the effect of post-curing process under elevated temperature. Polytetrafluoroethylene mould was adopted for the curing process of dumbbell adhesive specimens and both distilled and salt water were introduced to simulate a severe immersion environment. Quasi-static testing was conducted on both unaged and aged bulk adhesive after certain period of immersion to reveal the mechanical properties variation. Measurements on specimen weight and thickness were performed with different time intervals during the immersion process. It is shown that the strengths of bulk adhesive were significantly degraded due to the presence of water in both immersion conditions, where higher moisture content led to greater strength degradation regardless of the curing and ageing conditions applied. In addition, distilled water environment led to notably higher saturation content and hygroscopic swelling compared to salt water. However, the rates of water diffusion and hygroscopic swelling processes in salt water were detected to be far above the ones in distilled water. It is worth noting that slight increase was observed in moisture saturation content and swelling expansion for post-cured adhesive, while the coefficients of hygroscopic swelling showed no difference for all sample groups studied. Scanning Electron Microscopy observation further revealed the transition in microscopic topography from unaged to saturated samples.