Creation And Property Research Of Ionic Liquid Functionalized Polymer Material

Functional polymer materials are an important part of the field of polymer materials.Compared with ordinary polymer materials,they have many advantages.On the one hand,it have the properties of traditional polymer materials and on the other hand,their functionality can be shown through some special functional groups.Therefore,they can be the most widely used materials in the world,especially in the fields of medicine and environmental protection.With the continuous development of functional polymer materials in the aspect of biocompatibility and environmental friendliness,higher requirements are put forward for the controllable design and construction methods of these materials.Therefore,choosing a suitable functional groups to realize the efficient construction and application of functional materials has become the focus of general attention.Ionic liquids（ILs）are a kind of small molecular units with special properties and functions,and can provide new ideas for the designing and producing new materials.Polyionic liquids（PILs）are polymer materials with ionic liquid groups in the polymer backbone or side chains.From monomers to polymers,some special properties of ionic liquids can been transferred to polymers chain,such as thermal stability,low ionic fluidity,adjustable polymer structure,and wide electrochemical stability window.In addition,the structural design of ILs and the selectivity of polymer fragments enriched the applications of PILs,and which have attracted widespread attention in the polymer materials science.The research of structural design and controllable synthesis as well as performance and application of ionic liquid functional polymer materials can promote the development of polymer disciplines and expand the application fileds of functional polymer materials.This paper proposes some new synthetic strategies for preparing new polyionic liquids materials,characterizing their properties and exploring the applications.The main research contents and conclusions of the paper are as follows:（1）A porous polyionic liquid material with carboxyl functional was designed and prepared based on styrene-maleic anhydride copolymer（SMA）through a simple preparation method.The maleic anhydride group was attacked in-situ by the prepared small-molecule ILs compound to form a new carboxyl functionalized CILs-POF_mmaterial.The changes in the properties of the product were tuned by adjusting the molar ratio of small-molecule ILs.The chemical,physical structure and thermal properties of the materials were studied by FT-IR,NMR,TGA,DSC,XRD,SEM and BET.The application of this material in catalyzing the CO₂ cycloaddition reaction was explored.The results show that all crosslinked polyionic liquid materials have a mesoporous structure,and as the proportion of crosslinking agent（[Dhim][Br]）increases,the specific surface area of the product gradually increases.Under the same catalytic conditions（120°C,10 bar CO₂ pressure,6 h）,the catalytic activity gradually increases with the increase of the degree of cross-linking and can reach a maximum of more than 99%.The CO₂ cycloaddition reaction with other epoxy substrates also has a high yield.And the catalytic can be recovered by filtration and still maintan high catalytic activity even after five cycles of catalytic reaction.Not only that the chemical structure and physical properties of catalytic still remain stable.（2）A new material of carboxyl functionalized cellulose polyionic liquid（[Cellmim][Br]）was constructed through traditional transesterification reaction.The effects of molar ratio,reaction temperature and time on the properties of the product were explored.Afterwards,a new polyionic liquid POF-[Cellmim][Br]material with abundant mesopores was successfully prepared by in-situ cross-linking reaction.The structure and properties of those materials are revealed by FT-IR,NMR,TGA,DSC,XRD,SEM and BET.And the application of its catalytic CO₂ cycloaddition reaction has been systematically studied.The results show that the as-prepared[Cellmim][Br]material has a mesoporous structure and its specific surface area can reach 122 m² g^-1.The catalytic activity of CO₂ cycloaddition reaction by COF-[Cellmim][Br]-1material could be as high as 97%at 120℃,2 MPa and 4 h.The CO₂ cycloaddition reaction with other epoxy substrates also has a high yield.And the catalytic can be recovered by filtration and still maintan high catalytic activity even after five cycles of catalytic reaction.Not only that the chemical structure and physical properties of catalytic still remain stable.（3）The cellulose polyionic liquid membrane（Cell-PILs）material with a degree of substitution 0.32 was successfully prepared by a simple and easy-to-operate transesterification method.Subsequently,the Cell-PILs-CR,Cell-PILs-MO and Cell-PILs-SY membrane materials with pH responsiveness were prepared by anion exchange.The structure,pH response performance and recycling performance of those membranes were systematically characterized by NMR,FT-IR,EDX,UV-vis,and the relationship between the structure and the pH response performance was revealed.The results show that the different anionic dyes were successfully attached to the Cell-PILs membrane by ion exchange.The Cell-PILs-CR,Cell-PILs-MO and Cell-PILs-SY membranes have obvious pH response performance and good recycling performance.（4）The cellulose polycationic liquid（Cellulose-PILs）material was successfully prepared by the reaction of hydroxyl group,isocyanate and methyl imidazole.Its chemical structure was characterized by FT-IR and NMR.Afterwards,the self-healing hydrogel（Cellulose-PILs/PAAS）material was successfully prepared through the ion cross-linking reaction of Cellulose-PILs and sodium polyacrylate（PAAS）.The mechanical and self-healing properties of the self-healing hydroge material were characterized.Its electrochemical performance of the supercapacitor was tested through ionic conductivity,CV,GCD,EIS and cycle stability.The results show that the Cellulose-PILs/PAAS hydrogel material has good mechanical properties and self-healing properties.The electrochemical performance of supercapacitors with the solid electrolyte is excellent.Its ionic conductivity can be up to 84.5 m S cm^-1 and the working voltage up to 2 V.The mass specific capacitance is 122.3 F g^-1 at a current density of 1.0 A g^-1.The mass specific capacitance was still as high as 116.0 F g^-1even at-15℃,and its capacity retention rate was close to 95%of room temperature.The capacity retention rate was still above 80%after 8000 cycles of charge and discharge.And the hydrogel electrolyte still maintains good electrochemical performance after self-healing.