Study On The Oligomerization Of α-olefins Catalysized By AlCl₃-Et₃NHCl Ionic Liquid

AlCl3-Et3NHCl ionic liquid was synthesized as catalyst for oligomerization of a-olefins. PAO (poly-a-olefin) with Good viscosity-temperature characteristics and low temperature fluidity were synthesized from1-decene and1-dodecene. The optimum reaction conditions were studied. Infrared spectrum, nuclear magnetic resonance spectrum, gas chromatography and ReactIR system were used to characterize the oligomerizations.As for1-decene oligomerization, the mole ration of AlCl3/Et3NHCl is3, and the mass fraction of catalyst is5%, and the reaction temperature is100℃, the raction time is7h. At these conditions the kinematic viscosity of1-decene oligomerization is57.49mm2·s-1at40℃and9.94mm2·s-1at100℃, and the viscosity index of1-decene oligomerization is160, and the pourpoint of1-decene oligomerization is-63℃.As for1-dodecene oligomerization, the mole ration of AlCl3/Et3NHCl is3, and the mass fraction of catalyst is7%, and the reaction temperature is100℃, the raction time is8h. At these conditions the kinematic viscosity of1-decene oligomerization is90.88mm2·s-1at40℃and15.33mm2·s-1at100℃, and the viscosity index of1-decene oligomerization is178, and the pourpoint of1-decene oligomerization is-39℃.The IR spectrum of1-decene oligomerization and1-dodecene oligomerization showed that the oligomerization reactions are thorough, and the products have long linear side chains.1HNMR of1-decene oligomerization and1-dodecene oligomerization showed that there are more-CH2-and-RCH-than-CH3in the oligomerizations, which means that the oligomerizations have long linear side chains and low branching degree.13CNMR of1-decene oligomerization and1-dodecene oligomerization showed that the oligomerizations consists complicated keyed isomers. The gas chromatography showed that there is little raw material and dimer in1-decene and1-dodecene oligomerizations. The oligomerizations are mainly composed of trimer, tetramer and pentamer.The process of the oligomerization of1-decene was monitored by the ReactIR system. The IRs of reaction system at the stat, middle and end of the reaction were studied. And the changing trend of special peaks and4components with reaction time were studied too. The results showed that the oligomerization of1-decene and1-dodecene is cationic polymerization.