Particle removal mechanisms in synergistic aging of polymers and glass reinforced polymer composites under combined UV and water
Particle removal mechanisms in synergistic aging of polymers and glass reinforced polymer composites under combined UV and water
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DOI：
10.1016/j.compscitech.2017.10.028
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发表时间：
2017-12-01
影响因子：
9.1
通讯作者：
Kumosa, M.
中科院分区：
文献类型：
--
作者：
Lu, T.;Solis-Ramos, E.;Kumosa, M.
聚合物和聚合物基复合材料(PMC)在紫外线辐射和高温下水冷凝的协同老化过程中会发生复杂的降解过程。这种损伤与表面微粒的形成和随后缓慢流动的水将其清除有关。颗粒的去除显著加快了材料的整体降解过程[1]。在这项研究中，分析了流体动力学效应，以解释紫外线和水的协同老化对聚合物材料中微粒去除的影响。由缓慢流动的水在聚合物表面产生的粘性剪应力作为表面形态、流速和体积力的函数被确定。随后，通过将Johnson-Kendall-Roberts(JKR)模型和Hamaker方法计算的粘附力与慢速水流产生的阻力进行比较，提出了一种新的微粒去除机理。在实验部分，验证了在倾斜的单向玻璃/环氧树脂表面上的颗粒去除机理，其中环氧颗粒在水的重力作用下随机分布。研究表明，聚合物颗粒在聚合物/复合材料表面的运动强烈地依赖于颗粒尺寸、水流速度和表面形态。这项研究中提出的研究清楚地解释了为什么在偶尔缓慢的水流存在的情况下，紫外线对聚合物和玻璃钢的降解比仅仅通过个人暴露在紫外线辐射下要快得多。1.(C)2017爱思唯尔有限公司。保留所有权利。
Complex degradation processes occur during synergistic aging of polymers and Polymer Matrix Composites (PMCs) by UV radiation and water condensation at elevated temperatures. The damage is associated with the formation of surface micro-particles and their subsequent removal by slowly moving water. The particle removal significantly accelerates the overall degradation process of the materials [1]. In this research, hydrodynamic effects have been analyzed to explain removals of micro-particles from polymeric materials affected by synergistic aging by UV and water. Viscous shear stresses generated by slowly moving water were determined on polymer surfaces as a function of surface morphology, flow rates, and volumetric forces. Subsequently, a new micro-particle removal mechanism was suggested by comparing the adhesion forces calculated using the Johnson-Kendall-Roberts (JKR) model and the Hamaker approach with the drag forces created by slow water flows. In the experimental part, the particle removal mechanism has been verified on an inclined unidirectional glass/epoxy surface with randomly distributed epoxy particles subjected to a gravitational flow of water. It has been shown that the movement of polymer particles on polymer/composite surfaces depends very strongly on particle sizes, water velocity and surface morphology. The research presented in this study clearly explains why polymer and GRP degradation by UV in the presence of occasional slow water flows is much faster than just by the individual exposure to UV radiation reported in Ref. 1. (C) 2017 Elsevier Ltd. All rights reserved.