Cellulose nanomaterials as binders: Laminate and particulate systems
A novel application of cellulose nanomaterials, particularly cellulose nanofibrils (CNF) as a binder in conventional and novel laminate and particulate composite systems is discussed. Using cellulose nanomaterials as a reinforcing agent in conventional polymer composites faces several difficulties: 1) there are no easy ways to dry the CNF and maintain nanoscale dimensions, 2) there are compatibility issues related to cellulose-polymer bonding, and 3) there are issues related to obtaining a good distribution and redispersion of nanoscale materials inside a polymer matrix. An alternative strategy is applications in which cellulose nanomaterials can be used in the aqueous suspension form without first needing to dry them. In addition, applications should be targeted that take advantage of the impressive strength properties of these nanomaterials while capturing the nanoscale material property enhancements in the final product. It has been demonstrated that CNF is able to bond lamina of paper together to produce a new class of all-renewable paper nanolaminates with exceptional mechanical properties exceeding many reinforced plastic formulations. It has also been demonstrated that particleboard panels can be successfully manufactured without any added formaldehyde by complete replacement of urea-formaldehyde resin. Efforts to use cellulose nanomaterials in paper applications are also reviewed as well as adhesion mechanisms involved in such composite systems. The future outlook and potential market opportunities concerning this new application of cellulose nanomaterials, as well as known and potential limitations and challenges in the way of commercialization efforts, are presented.
Citation: Tajvidi, M., Gardner, D.J., and Bousfield, D.W., 2016. Cellulose nanomaterials as binders: Laminate and particulate systems. Journals of Renewable Materials, 4(5):365-376 doi:10.7569/JRM.2016.634103