Abstract: To study the effect of carboxyl group on the performance of amphoteric asphalt emulsifier and emulsified asphalt prepared from amphoteric asphalt emulsifier, three different asphalt emulsifiers were synthesized by using oleic acid, different molar ratio of diethylene triamine and chloroacetic acid, and their performances were characterized by infrared spectroscopy, surface activity and hydrophilic-lipophilic balance (HLB) value. The performances of emulsified asphalt prepared by different emulsifiers were tested. The research results show that: with the increase of carboxyl group in molecular structure of emulsifier, the surface tension of emulsifier at the critical micelle concentration (CMC) is increased from 37.42 mN/m to 40.24 mN/m and 43.98 mN/m; HLB value is increased from 8.1 to 11.1 and 13.9, which means that the water solubility becomes better; the demulsification rate of emulsified asphalt is from middle fission to fast cracking and then to slow cracking; the penetration at 25 ℃ of emulsified asphalt evaporation residue gradually decreases from 8.0 mm to 7.9 mm and 7.6 mm; the softening point successively increases from 47.0 ℃ to 47.5 ℃ and 48.5 ℃, and the hardness of asphalt increases.

Key words: highway engineering, emulsified asphalt, asphalt emulsifier, carboxyl group, surfactant, chloroacetic acid

摘要： 为研究羧基对两性沥青乳化剂及其制备的乳化沥青的性能影响，笔者利用油酸、不同摩尔比的二乙烯三胺和氯乙酸合成了三种沥青乳化剂，采用红外光谱、表面活性和亲水亲油平衡值表征其性能，对不同乳化剂制备的乳化沥青性能进行了测试。研究结果表明：随着分子结构中羧基的增加，乳化剂在临界胶束浓度下的表面张力由37.42增加到40.24和43.98 mN/m；亲水亲油平衡值由8.1增大到11.1和13.9，水溶性变好；乳化沥青的破乳速度从中裂变为快裂再到慢裂；乳化沥青蒸发残留物的25 ℃针入度由8.0减小为7.9和7.6 mm，软化点由47.0升高为47.5和48.5 ℃，沥青的硬度增大。

关键词: 道路工程, 乳化沥青, 沥青乳化剂, 羧基, 表面活性剂, 氯乙