摘要
为研究无砟轨道灌缝胶在紫外辐射作用下宏观粘附性能发展规律及微观机理,测试了灌缝胶的玻璃态转化点,对不同紫外老化时长下灌缝胶粘附性能变化规律进行研究,并基于原子力显微镜(AFM)方法研究了相同老化条件下灌缝胶微观DMT模量发展特性,分析了灌缝胶热力学特性、宏观力学行为与微观属性三者的相关性。研究结果表明,异氰酸酯指数(R值)的提高促使灌缝胶向双玻璃态转化点转变;R值与灌缝胶初始粘附强度呈正相关,与粘韧性及抗紫外老化性呈负相关;老化初期部分灌缝胶具有性能衰减滞后效应;微观方面,聚氨酯灌缝胶硬段是影响其粘附性的主要因素,且紫外辐射对硬段影响更为显著;此外,部分灌缝胶软段在紫外老化作用下的快速发展,导致其宏观结构泡沫化并丧失粘附性。
To study the developing rules and the micro-mechanism of the bonding properties of ballastless track sealants under ultraviolet aging,the glass transition point of sealants was measured,the developing rules of the adhesive properties of sealants were tested after various ultraviolet aging time,and the micro Derjaguin-Muller-Toporov（DMT）modulus of sealants was researched based on AFM equipment under the same aging conditions. The correlation analysis was then conducted among thermodynamic property,mechanical behavior,and micro properties. It is shown that for nonaged polyurethane sealants,isocyanate index（R value） motivates the sealants to double glass transition point material,and it has a positive relationship with the bonding strength,but a negative relationship with the tenacity and ultraviolet resistance ability. At the beginning aging period,some sealants present a lag effect of performance degradation. At the micro-level,the adhesive properties of polyurethane sealants were affected mainly by their hard phases,which were mainly affected by the ultraviolet aging. In addition,the rapid development of the properties of soft phase may lead to foaming of the micro-structure,and also loss of the adhesiveness.
作者
薛恒潇
谭忆秋
Hengxiao Xue;Yiqiu Tan(School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2018年第2期63-70,共8页
Polymer Materials Science & Engineering
基金
国家杰出青年科学基金资助项目(51225803)
国家自然科学基金资助项目(51478152)
关键词
无砟轨道
聚氨酯灌缝胶
低温粘附性能
紫外老化
DMT模量
玻璃态转化点
ballastless track
polyurethane sealant
bonding property at low temperature
ultraviolet aging
DMT modulus
glass transition point
