Abstract:The cationic surfactant of fatty alcohol-polyoxyethylene ether is a multi-functional surfactant

which played an important role in the industry of detergent

textile and so on. Fatty alcohol-polyoxyethylene ether chloride（AEO3-Cl）is the intermediate to synthesize the cationic surfactant of fatty alcohol-polyoxyethylene ether. The traditional halogenating reactions are always used the volatile organic solvents

which have great pressure to the environments. In addition

the drawbacks of those catalysts in halogenating reactions

such as

long reaction time and many by-products

are need to be solved. However

as the introduction of cleaner technologies has become a major concern throughout both industry and academia

the search for alternatives to the most damaging solvents and excellent catalysts has become a high priority. AEO3-Cl was synthesized via halogenation reaction of reactants fatty alcohol-polyoxyethylene ether (AEO3) and thionyl chloride (SOCl2) which was catalyzed by ionic liquid 1-octyl-3-methylimdazolium bromide ([OMIM]Br). The effects of reaction temperature

reaction time

amount of SOCl2 and the amount of [OMIM]Br on conversion rate of AEO3 were investigated. The structure of the synthesized product was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and H Nuclear Magnetic Resonance (1HNMR). The results showed that [OMIM]Br is an effective catalyst for the reaction in room temperature and the conversion rate of AEO3 is reaching over 99%

with the following optimum reaction conditions of AEO3:SOCl2:[OMIM]Br=1:1.3:1 (molar ratio)

the reaction temperature 25 ℃ and reaction time 30 minutes. The product was separated from the reaction mixture by extraction using n-hexane followed by the evaporation of n-hexane. The catalysts can be re-used for six times without obvious decreases of conversion

which showed that the catalysts have good recycling performances. In addition

it was suggested that the C2-H atom in [OMIM]Br could form hydrogen-bond with oxygen atom in hydroxyl group of AEO3

which reduces the reaction barrier

therefore led to high reaction rate and selectivity of the reaction. In summary

the [OMIM]Br has an excellent catalytic effect on the reaction. Notably

the [OMIM]Br is a nonvolatile compound

which have the advantages environmental friendly and nontoxicity.