微表处用改性咪唑啉型沥青乳化剂的合成及性能评价

Synthesis and performance evaluation of modified imidazoline asphalt emulsifier for micro-surfacing

以分子结构设计为基础,通过合成多头亲水活性基团、接枝改性增加咪唑啉型乳化剂的空间位阻,采用月桂酸、四乙烯五胺和丙烯酸甲酯为原料,利用在线红外监测咪唑啉中间体的官能团变化,合成改性咪唑啉型微表处用慢裂快凝型乳化沥青乳化剂,并对其进行性能评价。结果表明:合成的乳化剂性能优异,临界胶束浓度为23.99μg/g,在临界胶束浓度下表面张力为24.36 m N/m;用该乳化剂制备的乳化沥青颗粒均匀,体积平均粒径为3.09μm,乳化剂用量为1.5%时乳化沥青各项指标均满足微表处用乳化沥青的技术要求,与石料的可拌和时间达206 s。

On the basis of molecular structure design, the steric hindrance of modified imidazoline emulsifier was enhanced through synthesized multiple hydrophilic groups and graft modification. The modified imidazoline with slow-breaking and quick-setting performance for micro-surfacing was prepared using the lauric acid, tetraethylenepentamine and methyl acrylate, in which the online infrared spectrometer was used to track the characteristic absorption peak changes during the synthesis process. The results show that the synthesized emulsifier presents good surface activities, showing CMC of 23. 99μg/g and the surface tension of 24. 36 mN/m. The prepared asphalt emulsion has uniform particles of 3. 09 μm. It also meets the technical requirements for micro-surfacing at the emulsifier dosage of 1. 5%, in which the mixing time with aggregate can reach 206 s.