紫外老化沥青分子构成变化及其与流变性能和化学组成的构效关系  

Structure-activity Relationship Between Molecular Structure Change and Its Rheological Properties and Chemical Composition of UV Aged Asphalt

作　　者：席晗 孔令云[1,2] XI Han;KONG Lingyun(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;National and Local Joint Engineering Laboratory of Transportation Civil Engineering Materials,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学交通土建工程材料国家地方联合工程实验室,重庆400074

出　　处：《材料导报》2025年第6期82-90,共9页Materials Reports

基　　金：国家自然科学基金(51508062)。

摘　　要：为研究沥青分子量和分子结构构成在紫外老化作用下的变化及其对流变性能与化学组成的影响,以工程中常用的四种沥青为研究对象,分别进行了凝胶渗透色谱和核磁共振试验,探究了沥青紫外老化前后分子量、分子相对质量分布等分子量指标的变化以及氢谱图、碳谱图、氢原子含量、分子结构参数等分子结构指标的变化,并在流变性能试验基础上,采用关联分析法对沥青流变性能进行分子构成分析,从分子层面解释紫外老化作用下沥青流变性能的变化机理。结果表明:紫外老化使沥青内部分子发生团聚现象,小分子不断减少并聚集成大分子,分子量分布边界逐渐变窄。由氢原子和分子结构参数的变化情况可知,紫外老化后沥青中芳香环上烷基取代基增加,导致芳香环体积增大、沥青内部分子稳定性增强,宏观层面表现为沥青的流变性能下降。通过沥青流变性能和化学组成确定沥青的宏微观评价指标,并在采用关联法分析后发现,沥青流变性能受芳香环缩合度参数、芳香环周边氢取代率、数均分子量、芳香碳率、烷基和环烷支链、芳香结构的影响最大,且可对其进行机理分析。In order to study the molecular weight and molecular structure changes of asphalt under ultraviolet(UV)aging and their effects on rheological properties and chemical compositions,gel permeation chromatography and nuclear magnetic resonance tests were carried out on four kinds of asphalt commonly used in engineering.The changes of molecular weight index,such as molecular weight,molecular relative mass distribution,and molecular structure,and the molecular structure index including hydrogen spectrum,carbon spectrum,hydrogen atom content and mo-lecular structure parameters were studied before and after ultraviolet aging.On the basis of rheological properties tests,the molecular composition of asphalt rheological properties was analyzed by correlation analysis method,and the change mechanism of asphalt rheological properties during ultraviolet aging was explained from the molecular level.The results show that ultraviolet aging causes the agglomeration of molecules in asphalt,agglomerate,and small molecules decrease to into large molecules,and the molecular weight distribution boundary becomes narrower.From the changes of hydrogen atoms and molecular structure parameters,it can be seen that the alkyl substituents on the aromatic ring in the asphalt in-crease after ultraviolet aging,which leads to the increase of the volume of the aromatic ring and the increase of the internal molecular stability of the asphalt,and the decrease of the rheological property of the asphalt at the macro level.The macro and micro evaluation indexes of asphalt were determined by the rheological properties and chemical composition of asphalt.From correlation analysis,it was found that the rheological properties of asphalt were most affected by the condensation degree parameter of aromatic ring,hydrogen substitution rate around aromatic ring,number average molecular weight,aromatic carbon rate,alkyl and naphthenic branched chains,and aromatic structure.

关 键 词：沥青紫外老化 分子量 分子结构 流变性能 化学组成 

分 类 号：U414[交通运输工程—道路与铁道工程] TB332[一般工业技术—材料科学与工程]