贮存稳定的LDPE/SBS共混物改性沥青的制备

Preparation of storage stable LDPE/SBS Blend- modified Asphalt

比较直接添加LDPE、SBS改性沥青与LDPE/SBS熔融共混物改性沥青的高温贮存稳定性 ,并利用光学显微镜观察各种改性沥青在高温下随时间的变化。结果表明 :直接添加LDPE、SBS所得到的改性沥青 ,其高温贮存稳定性很差 ,在反应剂加入后得到了一定程度的改善。而采用预先制备LDPE/SBS共混物 ,再将其添加到沥青中 ,在反应剂存在的条件下 ,所得到的改性沥青能够在高温下稳定贮存。同时 ,相形态观察也表明 ,直接添加改性沥青 ,无论加入反应剂与否 ,都存在聚合物颗粒聚集现象。而共混物改性沥青的高温相形态则不随时间变化 ,这一点与稳定性测试结果相吻合。

In this paper, the Low Density Polyethylene (LDPE)/ Styrene-Butadiene-Styrene (SBS)blends prepared under high shear stress were used as asphalt modifiers. Compared to the asphalts modified by the LDPE and SBS added directly, the LDPE/SBS blends modified asphalts in the presence of reactive agent showed much better storage stability at high temperature. No visible phase separation was observed under an optical microscope at high temperature and the morphology analysis indicated that the phase structure of the LDPE/SBS blends modified asphalts was unchanged with time at high temperature. After stored at 163℃ for 48h , the LDPE/SBS blends modified asphalts had no evidence of coalescence of polymer particles.