马来酸酐接枝反应及其对沥青性质的影响

Grafting reaction with maleic anhydride and its effect on asphalt properties

通过均匀设计实验对酸酐化反应条件进行优化,利用FTIR,AFM等方法对反应前后沥青的常规性质、流变性质、化学组成、微观形貌变化等进行了研究。实验结果表明,在最佳反应条件(反应温度180℃、马来酸酐加量2%(w)、反应时间4.67 h、反应压力0.14 MPa)下,反应转化率可超过90%;酸酐化反应可以提高沥青弹性成分的占比,改善沥青的高温抗车辙性能、应力敏感性能,但对温度敏感性不利;改性沥青的胶质、沥青质增多,饱和分、芳香分下降,胶体结构由溶胶型向凝胶型转变;改性沥青中的蜂状结构高且锋利、数量更多、分布更密集,酸酐化反应使沥青质发生团聚,形成了强极性的胶团结构。

The reaction conditions for anhydride reaction were optimized by uniform design experiments,and the conventional properties,rheological properties,component composition,and microscopic morphology changes of asphalt before and after the reaction were studied by FTIR and AFM.The experimental results show that the reaction conversion can exceed 90%under the optimum reaction conditions of reaction temperature 180℃,maleic anhydride amount 2%(w),reaction time 4.67 h,and reaction pressure 0.14 MPa.Anhydride reaction can increase the proportion of elastic components in asphalt,improve the high-temperature rutting resistance and stress sensitivity of asphalt,but it is unfavorable to temperature sensitivity.The contents of colloids and asphaltenes of the modified asphalt increase,the saturated and aromatic components decrease,and the colloidal structure changes from sol type to gel type.The bee-like structure in the modified asphalt is high and sharp,with more quantity and denser distribution.The anhydride reaction makes the asphaltene agglomerate,forming a strongly polar micelle structure.