紫外老化对聚合物基复合材料剪切性能及孔隙结构的影响  

Effect of UV Aging on Shear Properties and Pore Structure of Polymer-based Composites

作　　者：王志航 许金余[1,2] 刘高杰 朱从进 WANG Zhihang;XU Jinyu;LIU Gaojie;ZHU Congjin(School of Aeronautical Engineering,Air Force Engineering University,Xi'an 710038,China;College of Mechanics and Civil Architecture,Northwest Polytechnic University,Xi'an 710072,China)

机构地区：[1]空军工程大学航空工程学院,西安710038 [2]西北工业大学力学与土木建筑学院,西安710072

出　　处：《材料导报》2022年第2期210-215,共6页Materials Reports

基　　金：国家自然科学基金(51208507,51378497)。

摘　　要：以苯丙乳液和醋酸乙烯-乙烯共聚乳液(VAE乳液)为有机组分制备的聚合物基复合材料为研究对象,采用实验室人工加速紫外老化的方法,对未老化和紫外老化1 d、7 d、15 d、30 d后的复合材料进行剪切试验和压汞测孔试验。通过测试复合材料的剪切强度、剪切峰值应变、剪切断裂伸长率、剪切韧度、剪切峰前韧度和孔隙结构,研究了紫外老化对复合材料剪切性能和孔隙结构的影响规律。结果表明:紫外老化能提高复合材料的剪切强度、剪切韧度和剪切峰前韧度,增强复合材料的剪切性能。随着紫外老化时间的延长,复合材料的剪切强度不断增大,紫外老化30 d后,复合材料的剪切强度提高了70.25%。复合材料的剪切韧度和剪切峰前韧度随着紫外老化时间的延长先增大后减小;紫外老化7 d后,剪切韧度提高了34.06%;紫外老化15 d后,剪切峰前韧度提高了101.68%。紫外老化在一定范围内提高了复合材料的剪切峰值应变,紫外老化15 d后,复合材料的剪切峰值应变提高了18.83%。由于光氧反应、水泥的二次水化反应和交联固化反应,经紫外老化后,复合材料的剪切断裂伸长率不断下降。紫外老化对复合材料的孔隙结构有较大影响,紫外老化7 d后,聚合物基复合材料的总孔隙量减少了18.00%。随着紫外老化时间的延长,复合材料的孔径分布逐渐向大孔径偏移。Polymer-based composites prepared with styrene-acrylic emulsion and VAE emulsion as organic components are the research objects.Using the method of artificially accelerated ultraviolet(UV)aging in the laboratory,the shear test and mercury intrusion test were carried out on the composites that were not aged and after 1 d(day),7 d,15 d,and 30 d UV aging.By testing the composites shear strength,shear peak strain,shear elongation at break,shear toughness,shear pre-peak toughness and pore structure parameters,the influence of ultraviolet aging on the shear properties and pore structure of composite materials was studied.The results show that UV aging can improve the shear strength,shear toughness and shear pre-peak toughness of composites,and enhanced shear performance of composite.With the prolongation of UV aging time,the shear strength of the composite material continues to increase;after 30 d of UV aging,the shear strength of the composites increased by 70.25%.With the prolongation of UV aging time,the shear toughness and shear pre-peak toughness first increase and then decrease;after 7 d of UV aging,the shear toughness increased by 34.06%;after 15 d of UV aging,the shear pre-peak toughness increased by 101.68%.UV aging increased the peak shear strain of the composites within a certain range,after 15 d of UV aging,the peak shear strain of the composites increased by 18.83%.Due to the photo-oxygen reaction,the secondary hydration reaction of cement and the cross-linking and curing reaction,after UV aging,the shear elongation at break of composites continues to decrease.UV aging has a greater impact on the pore structure of the composites.After 7 d of UV aging,the total pore volume of the polymer matrix composites was reduced by 18.00%.With the extension of the UV aging time,the pore size distribution of composites gradually shifted to larger pore sizes.

关 键 词：苯丙乳液 VAE乳液 水泥 复合材料 紫外老化 剪切性能 孔隙结构 

分 类 号：TU528[建筑科学—建筑技术科学]