Synergy in epoxy nanocomposites with cellulose nanocrystals and boehmite

The role of a stabiliser in the stiffening and strengthening of cellulose nanocrystal (CNC) filled epoxy was studied. Cetyltrimethylammonium bromide (CTAB), a cationic surfactant, and Boehmite (Boe) nanoclay were mixed with CNCs in water during processing. Boe and CTAB synergistically stiffened the CNC-epoxy composites, increasing elastic modulus by 72% over neat epoxy and 49% over unstabilised CNC-epoxy composites. Boe-treated CNC-epoxy composites exhibited a 23% increase in tensile strength over unfilled epoxy and a 63% increase over an unstabilised CNC-epoxy composite. These nanocomposites also maintained the strain-at-failure of neat epoxy and increased the storage modulus above T _g by 96%. This use of a naturally occurring alumina nanoplatelet as a synergistic stabiliser for CNCs provides a tremendous opportunity to reduce the use of surfactants in epoxy composites. This green filler system could be used to improve epoxy nanocomposites for structural components in automotive applications, construction materials and consumer products.