Synthesis Of Polyketone By The Combination Of Pd/CNT Catalyst And Ionic Liquid With Two Cyano-functional Goups

Polyketone prepared by the copolymerization of CO and styrene in the presenceof Palladium （II） is a kind of environmentally-friendly materials with great lightdegradation and biodegradation due to carbonyl exists in backbone. However, thePd-based catalyst which must be employed in the copolymerization is too expensiveand unrecyclable to be afforded by most chemistry industries. Therefore, we chose anovel catalyst support with huge specific surface area and strong metal-supportinteraction （SMSI）, carbon nano-tubes （CNT）. Then, the Pd/CNT catalyst wasprepared and employed to the copolymerization of CO and styrene so as to improvethe catalytic activity and reduce the reaction cost by increasing the recycled times ofPd-based catalyst. Furthermore, we synthesized a novelN-butylcyanide-N’-cyanoethylimidazolium hexafluorophosphate ionic liquid with twocyano-functional groups. The supported ionic liquid-Pd/CNT catalyst was used to thesynthesis of Polyketone, which is meant to further improve the catalytic activity.The purchased CNT was purified with treatment of boiling concentrated nitricacid, concentrated sulfuric acid and ultrasound. The Pd/CNT catalyst was prepared byimpregnation and characterized by XPS、DLS、XRD、HRTEM. The result shows thevalence of palladium supported on CNT is desired+2, the Pd²⁺supported on CNT isabout dozens of nano-particles and has a uniform distribution. Then, the Pd/CNTcatalyst was applied to the copolymerization of CO and styrene, and the productPolyketone was analyzed by IR,¹³C NMR, DSC, TGA, EA, XRD, HRTEM and GPC.Furthermore, the optimal technological conditions were searched out. The resultproves that the10%Pd/CNT catalyst can be recycled for14times and the highest totalcatalytic activity up to4239.64gPK/（gPd·h） can be achieved under the conditions:n（2,2’-bipyridine）/n(Pd²⁺)=3、 n（p-toluenesulfonic acid）/n(Pd²⁺)=3、n（p-benzoquinone）/n(Pd²⁺)=80、V（methnol）/V（styrene）=0.75、P（CO）=2MPa、reactiontemperatre=60℃、reaction times=2h.N-butylcyanide-N’-cyanoethylimidazolium hexafluorophosphate ionic liquidwith two cyano-functional groups was synthesized. The supported ionicliquid-10%Pd/CNT catalyst was prepared and applied to the copolymerization of COand styrene. The result proves that the supported ionic liquid-10%Pd/CNT catalystcan be recycled for11times and the highest total catalytic activity can reach4687.54gPK/（gPd·h）. Compared with traditional alkyl ionic liquid, cyano-functional ionic liquid has a more stable bonding with CNT, which enables the reactive species Pd²⁺tobe better protected. Therefore, it can further improve the catalytic activity. However,the presence of ionic liquid increases the viscosity and complexity of thecopolymerization system. Therefore, the recycled times of supported ionicliquid-Pd/CNT catalyst is decreased in comparison with Pd/CNT catalyst withoutionic liquid.