A study of different actions of glucanases to modulate microfibrillated cellulose properties

Glucanases provide an excellent option for pre-treatment of cellulose and improvement in properties of microfibrillated cellulose. In our research, we have used two different enzyme formulations, a purified β-1,4-endoglucanase, and an β-1,4-exoglucanase rich mixture and the focus of the study is on effect of high protein applications on PFI refined-microfibrillated cellulose (2,500 rev). At high protein applications, cellulose fibers showed improved fibrillation after endoglucanase treatment with 20.4% improvement over PFI-only refined fibers while the exoglucanase mix showed 6.8% improvement. At low protein applications, the purified endoglucanase treatment resulted in improved tensile, compression, Scott ply bond, extensional stiffness of microfibrillated cellulose compared with the exoglucanase mix or untreated refined fibers. Scott Ply Bond measurements are an indicator of hydroxyl groups on the fiber surface whose value increased with enzyme pre-treatment. Mechanical properties changed with enzyme treatment and suggest the bonding between fibers increases with endoglucanase treatment providing improved surface functionalization.