Modified Bentonite And Ionic Liquid Catalyzed Oleic Acid Polymerization To Dimer Acid

Under the dual pressure of environmental pollution and energy depletion,bioenergy will become the dominant direction in the development of materials and chemical industry.Dimer acid,a natural chemical product synthesized from oleic acid,is featured by low toxicity,wide sources and having renewable raw materials,which is an excellent raw material for the synthesis of organic polymer materials.At present,dimer acid is mainly produced on the bentonite catalyst in industry,but bentonite has disadvantages such as low activity,difficulty in recycle,and environmental pollution,which has brought a hard challenge to the development of the dimer acid industry.The key to solving the problem is to develop high active,environmentally friendly catalyst.Therefore,this paper focuses on the preparation of dimer acid by oleic acid polymerization.The preparation and characterization of modified bentonite and acidic functional ionic liquids and their application in oleic acid polymerization were studied.The result are as follows:(1)Bentonite was modified with AICl3,M9Cl2,ZnCl2,and modified bentonite was characterized by XRD,FT-IR,BET,and Py-IR.The results showed that after the modification of bentonite,the distance between layers increased,while the crystallinity decreased,and the structure changed little.The specific surface area,pore size and acid amount of modified bentonite were related to the type of chloride salt.(2)The modified bentonite was used for oleic acid polymerization and the activity of bentonite was found to be related to its structure.The active site in the tetrahedral structure has catalytic activity and the interlayer cation only affects the interlayer spacing,the more cations,the greater the interlayer spacing.With 3.6%MgC12/bentonite which has the highest activity as catalyst,the yield of dimer acid was 41.23%under the optimum reaction conditions,which was higher than 38.41%of bentonite.(3)Six different acidic functionalized ionic liquids were prepared and characterized with FT-IR,NMR,UV-Vis and Harnrnett,acetonitrile infrared,Py-IR,TG-DTG to determine the structure,acid strength,acid type and thermal stability of ionic liquids.(4)The ionic liquid was used for oleic acid polymerization.The catalytic activity of the ionic liquid was found to be related to the acid type and cation structure.The L acid played a major role in the catalytic reaction.The B acid synergistically catalyzed the hydrogen transfer reaction.The quaternary amine cation synergistically catalyzed Diels-Alder reaction.With[HO3S-(CH2)3-NEt3]Cl-0.71ZnCl2 which has the highest activity as catalyst,the yield of dimer acid was 34.63%under the optimum reaction conditions,which was close to the actual yield of dimer acid of bentonite,and the ionic liquid has good reusability and can realize the green synthesis of dimer acid.