The Research Of Drag Reduction Agent Synthetized By Ethylene/Alpha Olefin With Supported Ziegler-Natta Catalyst

In this thesis, the ethylene/α-dodecene copolymer was synthesized withTiCl₄/MgCl₂as main catalyst, Al （i-Bu）₃as cocatalyst and n-hexane as solvent, whichhad high molecular weight and adopted solution polymerization under normalpressure and pressurization respectively.The polymerization conditions that influencethe drag reduction rate of polymer were investigated by orthogonal test, and the bestpolymerization conditions were determined. FT-IR,¹³CNMR and XRD methodswere adopted to characterize the polymer and the loop evaluation device was used toevaluate the performance of polymer drag reduction.Under the condition of normal pressure, the optimum polymerization conditionsof synthesis of ethylene/α-dodecene binary copolymer that the volume percentconcentration of monomerα-dodecene was34.78%, ventilation time of ethylene was8min, main catalyst was0.05g,cocatalyst is0.2mL and reaction temperature was0℃.The drag reduction rate of the synthetic polymer was61.12%in this optimumpolymerization conditions.Under the condition of pressurized,the optimum polymerization conditions ofsynthesis of ethylene/α-dodecene binary copolymer were the main catalyst was0.4g,n （Al）/n （Ti） was80, V （α-dodecene）: V （n-hexane） was4:6and ventilation time ofethylene was8min.The drag reduction rate of the synthetic polymer was45.45%inthis optimum polymerization conditions.In the polymerization process of ethylene/α-dodecene, there was a comonomereffect, adding a small amount of ethylene can improve the activity of polymerization,the arrangement of polymer molecular chain was relatively loose, so that damaged theregularity of the polymer chain, the results of XRD show that a small amount ofethylene can reduce the crystallinity of copolymer, and the drag reduction rateincreased with the ethylene time. But withing the concentration of ethylene increased,the improvement of performance of drag reduction was not obvious. Finally, we evaluated the shearing performance of ethylene/α-dodecene polymerdrag reduction agent, found that both the American drag reduction agent and thehomemade ethylene/α-dodecene drag reduction agent were inevitably sheared anddegraded. However, in terms of the shear resistance and application value, theethylene/α-dodecene polymer was better than American drag reduction agent.