Synthesis, Characterization, Thermal Stability, and Kinetic Degradation of Cellulose p-Halide Benzoates in an Ionic Liquid 1-Butyl-3-methylimidazolium Chloride

Cellulose p-halide benzoates (C-p-HB) were synthesized by reacting microcrystalline cellulose (MCC) with p-halide benzoyl chloride (p-HBCl) namely; the p-Iodobenzoyl chloride (p-IBCl), p-Bromobenzyl chloride (p-BBCl), and p-Nitrobenzoyl chloride( p-NBCl) in ionic liquid 1-butyl-3-methylimidazolium chloride [Bmim](Cl) at 60 degrees C for 2 h in the presence of 4-dimethylaminopyridine (DMAP) as a base. The synthetic products were characterized through infrared spectrometry (FT-IR), nuclear magnetic resonance (NMR) spectroscopy, XRD, and scanning electron microscopy (SEM). Then, the effects of p-halide benzoate groups on the thermal degradation of C-p-HB esters with DS approximate to 1 were investigated using thermogravimetric analysis under an inert atmosphere from room temperature to 600 degrees C at a heating rate of 5 degrees C/min. The DSC analysis was used to determine the glass temperature and heat of the reaction of C-p-HB esters. The results indicated that the C-p-HB was successfully synthesized in [Bmim](Cl) with a DS approximate to 1. The kinetic parameters were determined by the Coats-Redfern (CR) method. The corresponding kinetic parameters of the main degradation stages were also determined. The thermal stability of MCC was remarkably decreased through esterification with p-HBCl. The Criado method was used to determine the most probable degradation functions. Thus, reaction orders F2 and F3 were most probably the functions that describe the degradation of C-p-HB.