Hydrogels Prepared from Cross-Linked Nanofibrillated Cellulose

Nanocomposite hydrogels were developed by cross-linking nanofibrillated cellulose with poly(methyl vinyl ether-co-maleic acid) and polyethylene glycol. The cross-linked hydrogels showed enhanced water absorption and gel content with the addition of nanocellulose. In addition, the thermal stability, mechanical strength, and modulus increased with an increase in the amount of nanocellulose in hydrogels, and this can be attributed to efficient cross-linking between the nanocellulose and the matrix. The addition of softwood nanocellulose showed much higher strength and strain properties in the hydrogels than with the addition of hardwood nanocellulose. The enhanced physical properties confirm that in situ cross-linking of nanofibrillated cellulose with the matrix polymer forms hydrogels that are not just blends of starting materials but are distinctively unique and formed by cross-linking interactions between the filler and matrix.