Study on synthesis of enzymatic hydrolysis lignin modified amine as an asphalt emulsifier

Emulsified asphalts are popular at recent years for saving energy to melt solid asphalt. Emulsifier is very important for emulsification of asphalt. Enzymatic hydrolysis lignin modified amine (EHLA) was synthesized by Mannich reaction of enzymatic hydrolysis lignin (EHL) with formaldehyde and triethylene tetramine (TETA). The structures of the product was analyzed by FT-IR, and the influence of process parameters such as the molar ratio of formaldehyde to TETA, the reaction temperature and time were discussed. According to the results, the optimized technological conditions were as follows: the reaction temperature was 80°C, the molar ratio of formaldehyde to TETA was 1.6 : 1, reaction time was 3 h, and the weight of lignin was 25 g. The result of emulsification shows that EHLA could be an effective and slow set cationic asphalt emulsifier.