Synthesis of [AEIM]Cl and Its Dissolution of Microcrystalline Cellulose by Microwave

A novel ionic liquid,1-allyl-3-ethyl imidazolium chloride([AEIM]Cl),was synthesized and its chemical structure was confirmed by FT-IR and 1H NMR.The solution of microcrystalline cellulose(MCC)in [AEIM]Cl was prepared by microwave heating.Influences of three treatment methods,such as NaOH,microwave and high pressure,on the crystallinity,degree of polymerization(DP)and dissolution rate of MCC were studied.Chemical structure,change of crystal form,thermostability and appearance of the regenerated cellulose after dissolution were analyzed by FT-IR,XRD,TGA,and SEM,respectively.It showed that the ionic liquid was a direct solvent for MCC.Compared to original MCC,crystallinity of MCC treated decreased from 92.0% to 49.2%,DP decreased from 306 to 153,and dissolution rate increased from 5.2% to 28.8% when the MCC was treated with 15%(mass fraction)NaOH in a high pressure pot at 140 ℃.Chemical reaction did not occur during the dissolution of MCC.Crystal form of the regenerated cellulose changed from original cellulose Ⅰto cellulose Ⅱ,crystallite dimension of the regenerated cellulose was decreased from 4.92 nm to 1.76 nm,and thermal decomposition temperature decreased from 246.6 ℃ to 183.0 ℃.