吸湿对单向亚麻纤维复合材料力学性能的影响  

Influence of moisture absorption on the mechanical properties of unidirectional flax fibre composites

作　　者：贾云龙 FIEDLER Bodo JIA Yunlong;FIEDLER Bodo(School of Aerospace and Mechanical Engineering/Aviation,Changzhou Institute of Technology,Changzhou 213032,China;Institute of Polymer and Composites,Hamburg University of Technology,Hamburg D21073,Germany)

机构地区：[1]常州工学院航空与机械工程学院/飞行学院,常州213032 [2]汉堡工业大学聚合物与复合材料研究所,汉堡D21073

出　　处：《复合材料学报》2022年第2期608-616,共9页Acta Materiae Compositae Sinica

基　　金：常州工学院高层次人才科研启动项目(YN20075);国家建设高水平大学公派研究生项目(留金发[2015]3022)。

摘　　要：为探明亚麻纤维增强树脂复合材料(FFRPs)在长期潮湿环境中的力学性能变化规律,基于真空辅助树脂模塑传递成型(VARTM)手段制备了的干燥状态的单向FFRPs(纤维体积分数为40vol%)。试验研究了FFRPs在30°C、80%相对湿度(RH)环境中放置5天、35天、86天后拉伸力学性能变化。结果表明,FFRPs在湿热环境中吸水量近似符合一维情况下的Fickian第二定律,饱和吸水量为5.3%左右。FFRPs在垂直于纤维方向上的拉伸强度和模量随吸湿度增加递减,断口微观分析表明吸湿降低了纤维基体界面结合性能。然而,FFRPs在纤维方向上的拉伸强度并未因吸湿降低,反而在吸湿过程呈现出先减小后增加的趋势,此变化规律文献中尚未报道:相比干燥状态,放置5天后拉伸强度下降5.7%;放置35天后拉伸强度增加18.7%;放置86天时样品已处在饱和吸湿状态,拉伸强度略微减小,但仍比干燥状态增加13.7%。FFRPs在纤维取向上拉伸强度变化可解释为多因素共同作用的结果。This paper investigated the evolution of mechanical properties of flax fibre reinforced polymer composites(FFRPs) conditioned in humid condition for a long term. Dry unidirectional FFRPs having fibre volume fraction of 40 vol% were manufactured via vacuum assisted resin transfer moulding(VARTM). FFRPs were conditioned in 30°C, 80% relative humidity(RH) for different time(5 days, 35 days and 86 days) and their tensile properties were tested and analyzed. The results demonstrate that the moisture absorption of FFRPs fairly follows one dimensional Fickian’s second law. The equilibrated water content is around 5.3%. Tensile strength and modulus perpendicular to fibre direction decrease with moisture absorption. Fracture morphology shows that fibre-matrix bonding strength decreases after moisture absorption. Tensile strength in fibre direction is not degraded by moisture absorption, and exhibits a trend featured by a first drop followed by an increase, which has not been reported in literatures.Tensile strength in fiber direction decreases by 5.7% after being conditioned in humid for 5 days, and increases by18.7% after 35 days. Further absorption of moisture up to 86 days(already saturated) causes a slight decrease in tensile strength but is still 13.7% higher than that at dry state. The change trend of tensile strength in fibre direction during moisture absorption can be explained as a consequence of averaging effects of several factors.

关 键 词：植物纤维复合材料 亚麻纤维 吸湿 拉伸力学性能 耐久性 

分 类 号：TB332[一般工业技术—材料科学与工程]