Study On The Polymerization Of 1,3-pentadiene Catalyzed By Et₃NHCl-ZnCl₂ Ionic Liquid

With the rapid development of China’s ethylene industry, The capacity of C₅ fraction resources（about 14-17% of ethylene production） is increasing. At present, the comprehensive utilization of C₅ fraction is less than 15% in China. Compared with40%-80% utilization C₅ fraction in the developed countries,the deference is large and obvious. Carrying out the new technologies to promote the comprehensive utilization of the active ingredient in the C5 fraction is one of the important issues in the development of the petrochemical industry. And beneficial for promoting the economic growth model of petrochemical industry and for improving of petrochemical products comprehensive processing technology level, achieving circular economy development.1,3-pentadiene is the largest ingredient of C5 fraction,（about 65%）.Most of them is used for the production of C5 aliphatic petroleum resin. Since the resins are saturation, low density, good water resistance, it is widely used in traffic paint, coating and other industries.Currently, traditional methods for preparing 1,3-pentadiene petroleum resin are employing AlCl₃ as the catalyst, as AlCl₃ is very activity, it is easy to implosion to generate a lot of insoluble substances in the polymerization. It also generate large amount of waste containing chloride and aluminium ions by removing AlCl₃ catalysts, the quality of the products are poor. Therefore, the development of new catalytic system is of significance.In this report, poly（1,3-pentadiene） was synthesized with a moisture-stable Et₃NHCl-n ZnCl₂ ionic liquid as the catalyst, the optimal polymerization condition was obtained as follows : temperature 90℃,t=10h,V（CHCl₃）=50m L, X（ZnCl₂）=0.72,Et₃NHCl-n ZnCl₂:51.8wt%.The molecular weight of the product was 2500,the yield was 59.4% and the softening point is 102℃. The product contains no insoluble fractions in the whole range of monomer conversions and polymerization conditions and shows potential for further industrial development. Moreover, Et3NHCl-ZnCl₂ ionic liquid is used for copolymerization of styrene and concentrated 1,3-pentadiene to improve the yield of the polymer.Compared with traditional AlCl₃ catalyst, Et₃NHCl-ZnCl₂ ionic liquid has a moderate catalytic activity, water stable, easy separation, and environmental friendliness. It has the important guiding significance for the development of the synthesis technology of the high performance 1, 3-pentadiene resin.