Continuous production of cellulose mixed esters via homogeneous reactive twin-screw extrusion catalyzed by ionic liquid

Abstract Cellulose mixed esters (CMEs) substituted with two different types of acyl groups are promising polymeric materials various tunable properties but arduous to produce. This is because the insolubility cellulose in common solvents, and thus, industrial production CMEs desired degrees substitution (DSs) requires a costly multistep process. To accomplish their facile production, homogeneous reactions have been performed using ionic liquids (ILs) as solvents for cellulose. However, high viscosity cellulose-IL solutions causes insufficient mixing batch reactors; thereby, favoring low concentrations long reaction times (typically hours). Herein, we demonstrate rapid scalable by exploiting excellent shear twin-screw extruder flow reactor. A co-solvent system comprising an IL, 1-ethyl-3-methylimidazolium acetate, dimethyl sulfoxide was applied dissolve at concentration (15 wt.%) via extrusion. During continuous extrusion 80 °C, reacted reagents, isopropenyl acetate (IPAc) vinyl propionate (VPr) (2.5:0.5, mol/mol), yield (CAP) within minutes. The CAP stably produced during operation time 50 min average isolated 71%. DSs acetyl propionyl were 1.77 0.50, respectively, corresponding sufficiently conversion rates 70% IPAc 100% VPr.