基于凝胶渗透色谱法的改性沥青中SBS降解行为研究

Degradation process of SBS in modified asphalt based on gel permeation chromatography analysis

为了探明改性沥青中SBS(苯乙烯-丁二烯嵌段聚合物)在施工及使用过程中的老化行为,通过对改性沥青在RTFOT、PAV老化前后的凝胶色谱分析研究了SBS的降解过程。结果表明:改性沥青经历RTFOT老化后有少量SBS交联结构发生降解,对沥青仍具有较好的改性效果;改性沥青经历PAV老化后SBS发生严重降解,平均分子质量显著下降,部分SBS丧失对沥青的改性效果;线性和星型2种类型SBS的老化程度不同;荧光显微观测试验结果与GPC分析结论一致,证明GPC分析方法能有效表征SBS的降解过程。

In order to study the aging behavior of SBS in the production and usage of modified asphalts,the degradation of SBS were studied through gel permeation chromatography （GPC） analysis before and after the RTFOT aging and PAV aging of SBS modified asphalts. The results show that：the degradation of SBS is minor reaction in the RTFOT aging, and it still has the effect of modifying asphalt after aging;SBS has gross degradation and lost the effect of modifying asphalt with the significant declining of molecular weight after PAV aging. The degradation of linear SBS and radial SBS is different. The conclusions of fluorescence micrograph test and GPC method are equivalent,and it proves the GPC method can explain the degradation mechanism of SBS.