Cellulose nanocrystals (CNC) have been receiving increasing attention in recent years due to their unique properties and potential applications in a broad range of industries. Specifically, CNC has extraordinary mechanical properties and high surface area which are desirable for nanocomposite applications. However, the hydrophilicity of CNC hinders its dispersion in nonpolar polymers as well as organic solvents. Therefore, it is necessary to modify the CNC surface properties to enhance its compatibility with organic media and nonpolar polymers. The functionalization of CNC by using polymer chains, compared with small molecules, might be more versatile since both polymer chain density and length could be adjusted during the functionalization process, imparting great flexibility to this type of work. In the present work, double bonds were introduced onto the CNC surface through a mild esterification reaction. Then radical addition was employed to graft polymer onto the CNC surface. The model monomer and polymer used were methyl acrylate (MA) and poly(methyl acrylate) (PMA), respectively. The influence of grafted PMA molecular weight on the PMA graft density was systematically studied and discussed. Moreover, the prepared PMA grafted CNCs were further characterized in terms of chemical composition (DRIFT-IR, elemental analysis, and XPS), dispersion stabilities and properties in a variety of organic solvents (UV-Vis and dynamic light scattering), crystal structure (XRD and CP/MAS 13C NMR) as well as morphology (TEM). The present work has demonstrated a facile and versatile approach using radical addition for grafting polymer onto CNC surfaces.

Functionalization of cellulose nanocrystals with polymer grafts: A facile and versatile grafting-to approach

247th National Meeting (2014)

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