(542c) Surface Functionalization of Nanocrystalline Cellulose
The chemical modification of nanocrystalline cellulose (NCC) mainly occurs on the surface by introducing functional groups to meet the needs of different applications. The chemical reactions modify the hydroxyl groups of cellulose primarily by esterification, silylation, oxidation and etherification. TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) mediated oxidation selectively converts hydroxymethyl group into carboxylic group on the surface of cellulose, which results in a better dispersion of HCl-hydrolyzed NCC. Most of previous efforts on surface functionalization have been focused on the chemical modification of hydroxyl groups of cellulose and improve NCC dispersion in polar organic solvents or its specific mechanical applications. Few researchers have focused on the chemical modification or polymer grafting of NCC to be dispersed in non-polar solvents.
In this study, we will use polyisobutylene succinic anhydride (PIBSA) to graft a hydrophobic tail on the surface of NCC. The succinic anhydride can covalently bond with hydroxyl groups through esterification. In the process, NCC will react with polyisobutylene succinic anhydride (Mw ~950-1300) in toluene at 100°C for 5-30 min. Finally, the resulting nanocellulose-PIBSA will be collected via centrifugation. The grafted NCC will be dispersed in non-polar solvents by mechanical and ultrasonic mixing with the disperser homogenizer. In addition, (2-dodecen-1-yl) succinic anhydride with lower molecular weight will also be used in the polymer grafting to examine the effect of short alkyl chain on the dispersion of NCC.