Synthesis Of Functional Cellulose Materials Using Ionic Liquid As Homogenous Reaction Medium

Cellulose has many advantages, such as biodegradable, renewable, cheap. However, due tothe existance of hydrogen-bonded supramolecular structures in cellulose, it is extremely difficultto dissolve cellulose in water and most common organic solvents. The insolubility of cellulosehas become a bottleneck for its application. It was found that the ionic liquid has good solubilityof cellulose. Besides, the ionic liquid have many advantages, such as enhanced electrochemicalstability and thermal conductivity, and especially have a broader selection of anion and cationcombinations. Therefore, the ionic liquid has been widely used in cellulose dissolving andprocessing modification. It didn’t require the activating treatment of cellulose and diminishedcellulose degradation that ionic liquids were utilized as the solvent of cellulose in mildconditions. Therefore, the emergence of ionic liquids as cellulose dissolution and derivatizationreaction has opened a new page. The homogeneous modification of cellulose has manyadvantages,such as relativelyshorterreaction timeandgood physicalandchemicalproperties.Theresearch objectofthisthesis include:(1) The homogeneous graft copolymerization of MMA onto cellulose using1-buty1-3-methylimidazoliumchlorideionic liquid ([Bmim]Cl)as reaction mediumwas studied.The result showed that the optimum conditions are as follows: the content of MCC,4.60wt%;the content of MMA,6.91wt%; the content of initiator,0.55wt%; reaction temperature,65℃and reaction time,2h, the grafting ratio could reach72%. According to the absorbingexperimental determination of water absorption of graft copolymer ratio can reach145.39%.Moreover,the structureofthegraftcopolymerwascharacterized bymeansofFTIR,TG,SEM.(2) The homogeneous graft copolymerization of styrene was carried out using1-buty1-3-methylimidazolium chloride ([Bmim]Cl) ionic liquid as reaction medium,(NH4)2S2O4as initiator, N’N’-methylene bisacrylamide (MBA) as cross linker. The effects ofmonomer concentration, reaction temperature and other experimental conditions on the graftingyield were investigated. The results demonstrate that under the efficient reaction conditions: thecontent of MCC,4.42wt%; the content of St,11.05wt%; the content of initiator,0.27wt%; reaction temperature,60℃and reaction time,2h, the grafting ratio could reach87.27%. Theresults of TGA indicated that cellulose grafted PS (cellulose-g-PS) had higher thermal stabilitythan that of ungrafted regenerated cellulose (reg-cellulose). SEM showed that cellulose-g-PSdisplayedhomogeneousmorphology.(3) The structure of the ionic liquid was characterized. Ionic liquid recycling experimentsshow that ionic liquid can be recycled reuse, which was expected to provide a new method forthehomogeneous modification and cellulosematerialprocessing.