Research Of α-methylstyrene Dimerization With High Atom Economy

α-methylstyrene(AMS) is the byproduct of industrial process producing phenol and acetone. This process is the main way to yield phenol and acetone in our country. With the increasing output of AMS, how to utilize AMS is becoming an urgent problem. The dimerization of AMS is a promising research field and much attention has been paid to this domain in last decade.The dimers of AMS have been applied in chemical industry widely. The linear dimers are used as the controlling agents of molecular weight in the production of copolyrriers, such as styrene-butadiene rubber(SBR). The linear dimer 2,4-diphenyl-4-methyl-l-pentene is also an alternative for dodecylmercaptane. Adding cyclic dimer into polyethene(PE) can increase flowability, improve processability and decrease melt viscosity, processing temperature of PE plastics. The hydrogenated forms of AMS dimers are of industrial value as component in lubrication compositions.The research work is focused on the dimerization of AMS catalyzed by ionic liquids Et3NHCl-AlCl3 and Et3NHCl-FeCl3. We find that Et3NHCl-AlCl3 possesses very good performance of catalysis for the cyclic dimerization of AMS. The reaction of the dimerization of AMS is carried out without the presence of solvent for five minutes, AMS converts to products totally, and the selectivity of cyclic dimer is very high(>90%). When using Et3NHCl-FeCl3 as the catalyst, we can get the cyclic dimer or linear dimers by adding solvent with different polarity.In this paper, we also select SBA-15 supported PW (PW/ SBA-15) as catalyst of the dinierization of AMS. The results indicate that PW/ SBA-15 is a good catalyst of this reaction. The conversion of AMS and the selectivity of cyclic dimer reach 100% in the experimental conditions. This process embodies 100% atom economy, and no pollutant releases during the reaction. The results indicate that PW/ SBA-15 is a green catalyst of AMS dimerization.