Synthesis And Study Of Vinylene Carbonate And Fluoroethylene Carbonate

Vinylene carbonate can be used for various applications in organic chemistry, its mainapplication as an additive for lithium batteries, as a component of surface coatings or as amonomer for the preparation of polyvinylene carbonate and other polymer monomer.Vinylene carbonate also can be used for lithium batteries and lithium ion batteries as anonaqueous electrolyte. As a new electrolyte, fluoroehylene carbonate can form wellSEI-film, its structure is closeness and don’t increase electrical impedance which preventthe decomposition of the electrolyte and advance the life-span of lithium batteries.Preparation of vinylene carbonate and fluoroethylene carbonate are described in thispaper, the synthetic route of vinylene carbonate and fluoroethylene carbonate are designed.With ethylene carbonate as starting material, the intermediate chloroehylene carbonate canbe obtained after chlorination. Then vinylene carbonate was synthesized throughdehydrochlorination with choloehylene carbonate and triethylamine; fluoroethylenecarbonate was synthesized through substittion reaction with choloethylene carbonate andpotassium fluoride. The final compound and intermediate compound was analyzedqualitatively by1H-NMR, IR and GC etc.,the structure of the product was determined.Simultaneity, we optimized the reaction conditions and feasibility of the synthetic route wasconfirmed.The results show that: synthetic choloethylene carbonate:(1) with ethylene carbonateas material, without solvent, reaction temperate65℃, addition0.1%AIBN, reaction time7h, chloroehylene carbonate percent conversion was46.0%;(2) with ethylene carbonate asmaterial, carbon tetrachloride as solvent, reaction temperate65℃, addition0.1%AIBN,reaction time6.5h, chloroehylene carbonate percent conversion was79.4%, afterrectification under vacuum, the yield is66.8%, purity is98.1%. Synthetic vinylene: withuntreated ethylene carbonate as material, dehydrochlorination with triethylamine, reactiontemperate35℃, n(triethylamine):n(CEC)=1.5:1, reaction time2.5h, CEC content46.0%~50.1%, the yield is68.7%, purity is99.3%.. After recrystallization and rectification,the recovery of refining is77.5%, purity is99.95%, achieve the requirement of lithiumbattery level. Synthetic fluoroethylene carbonate: with prepared ethylene carbonate asmaterial, methyl cyanide as solvent, polyethylene glycol800as phase transfer catalyst,reaction temperate55℃, reaction time6h, n(methyl cyanide): n(CEC)=3.5:1, n(KF):n(CEC)=1.3:1, the yield is75.1%, purity is95.1%. After two recrystallizations andrectification, the recovery of refining is70.4%, purity is99.98%, achieve the requirementof lithium battery level.