Syntheses, Preparations And Application Of Ionic/Nonionic Composite Asphalt Emulsifiers

Asphalt with water-resistant, moisture resistance, toughness, wear resistance and other advantages are widely used in road construction. Owing to the disadvantages of high viscosity and poor liquidity under room temperature of asphalt, it can not be crushed down to the aggregates to make mixed homogeneity. There are two conventional methods to mix asphalts with aggregates, one is solvent method and the other is high temperature melting method. It shows that the former need a large number of solvents and the latter burn up a great deal of fuels. Both of methods release large amounts hazardous gases which result in pollution of the environment. Asphalt emulsified technology comes up to deal with this problem well. The emulsified asphalt is a thermodynamically instable system which asphalt particles homogenized disperse in emulsifier aqueous solution. The performance of emulsified asphalt depends on the emulsifying capacity of the emulsifier. Thus, the key factor of emulsified asphalt is to research the emulsifying capacity of the emulsifier.Emulsified asphalt is a kind of surface active agent. Its developing path goes through a transition from anionic type to cationic type and non-ionic type. One single kind of emulsified asphalt can't be used with different types of asphalts or aggregates to meet the demands of different conditions or road performances required. The composition, of different types of emulsifiers, will effectively improve the inadequacy of single emulsifier.This paper uses OP-10and PEG to react with epoxy chloropropane respectively to make nonionic intermediates, and then use the nonionic intermediates respectively to react with organic amine to make two kinds of ionic/nonionic composite asphalt emulsifiers. We have explored the effects of reacting conditions and proportions on emulsifiers' synthesis, emulsifying ability, stableness of storage of emulsified asphalt and the needs of roads construction. We have structured the PEG/cationic composite asphalt emulsifiers with IR, and we have also measured its surface tension and critical micelle concentration. According to the specifications, we have relevant tests on the performances of emulsified asphalts and evaluated the emulsifying ability, concluded as follows:(1) OP-10/cationic composite asphalt emulsifierThe synthesis formula and proper conditions of the nonionic intermediate are: molar ratio of OP-10and epoxy chloropropane is1:1.4, the reacting temperature is85℃, the reacting period is16h and with the catalysis of concentrated sulfuric acid of1.0%weight fraction.The synthesis formula and proper conditions of the composite asphalt emulsifier are:molar ratio of the nonionic intermediate, polyethylene polyamine is1:1.1, the reacting temperature is90℃, the reacting time is6h and the solvent is isopropyl alcohol.(2) PEG/cationic composite asphalt emulsifierThe synthesis formula and proper conditions of the nonionic intermediate are:molar ratio of PEG and epoxy chloropropane is1:1.1, the reacting temperature is80℃, the reacting period is12h and with the catalysis of concentrated sulfuric acid of1.0%weight fraction.The synthesis formula and proper conditions of the composite asphalt emulsifier are:molar ratio of the nonionic intermediate and octadecyl propane diamine is2.2:1, the reacting temperature is95℃, the reacting time is7h and the solvent is isopropyl alcohol.Critical micelle concentration of the emulsifier is256mg/L, and the surface tension is33.521N/m under the density.The test on the emulsifying ability of the emulsified asphalts shows: the two emulsified asphalts are also slow cracked with high performances of emulsifying ability under different pH and different brand asphalt. The emulsifying ability of emulsified asphalts meets the demands of emulsified asphalts for roads of highway asphalt pavement construction technology standard JTG F40-2004.