Synthesis Of Fluoroethylene Carbonate

Fluoroethylene carbonate can be used as medicine and pesticide intermediates, mainly usedfor the additive of lithium ion battery, it can form a layer of the excellent performance of the SEIfilm to reduce the battery impedance, partial inhibition of electrolyte decomposition, it cansignificantly improve the specific capacity of battery and improve battery cycle stability,fluoroethylene carbonate also has the effect of flame retardant, thus improving the safety of thebattery.At present the industrial production of fluoroethylene carbonate are aways use lluorine gasto proceed direct fluoride. Based on a certain percentage of F2and inert gas mixture at a certaintemperature directly fluorinated reaction with the ethylene carbonate. Because of the F2canFurther react with the fluoroethylene carbonate, generate more fluoride side product. Thus thismethod caused very great difficulty on control response, so the requirements of equipment andproduction technology are very high, and the fluoride toxicity on environmental pollution,excessive fluorine gas is a big environmental risks and the treatment is also difficult.In order to improve the yield and quality of product, reduce the environmental pollution andexplore more economic process we optimized the synthesis process of the fluoroethylenecarbonate:Firstly chloroethylene carbonate was prepared by chlorination of ethylene carbonatewith sulfuryl chloride as chlorinating agent and azobisisobutyronitrile as an initiator,thenchloroethylene carbonate reated with posassium fluoride which functioned as a fluorinating agentin a solution to give fluoroethylene carbonate. We identified the optimum process conditions ofSynthesis of fluorinated ethylene carbonate: Chloroethylene carbonate (CEC) was prepared bychlorination of ethylene carbonate (EC) with sulfuryl chloride as cholorinating andazobisisobutyronitrile (AIBN) as an initiator. CEC reacted with Potassium fluoride (KF) whichfunctioned as a fluorinating agent in a solution to give Fluoroethylene Carbonate (FEC). Theoptimum technological conditions for preparing CEC were as follows: the reaction taken place at65℃; sulfuryl chloride was added into the reaction solution in drops in60min and reacted for90min; the molar ratio of ethylene carbonate(EC) and sulfuryl chloride was1:1.3, the amount ofsubstance ratio of AIBN to EC was n（AIBN）:n（EC）=1:200. The yield of CEC could reach to85.81%under such reaction conditions. The optimum technological conditions for preparing FECwere as follows: acetonitrile was chosen as the solvent, the reaction temperature was75℃, thereaction time was1.5to2h, the molar ratio of CEC and KF was1:1.3. Under these reactionconditions, the yield of FEC could reach to71.86%. The product was characterized by means of IR and GC-MS.This process can shorten reaction time, improves the product yield, less environmentalpollution, more suitable for industrialized production...