Surface-modified cellulose nanocrystals for biobased epoxy nanocomposites

Herein a unique strategy for cellulose nanocrystal functionalization is presented in the form of surface functionalization of cellulose nanocrystals. Cellulose nanocrystals were prepared from acid hydrolysis of ramie fibers and then further subjected to amine functionalization with an amino trimethoxy silane (APTMS). The introduction of surface amine functionality to the cellulose nanocrystal allowed for an additional reaction with a biobased epoxy resin derived from diphenolic acid. The resulting thermomechanical properties of epoxy nanocomposites with amine functionalized cellulose nanocrystal were on average more than 7 times improved. Specifically, the storage modulus at 160 °C increased from 19.5 MPa for the neat resin to 151.5 MPa for the composite with 10 wt% APTMS modified CNC. The results reported herein demonstrate that amine functionalized cellulose nanocrystals provide excellent dispersion in epoxy resin systems and are a viable route to utilization of both biobased nanofillers and biobased epoxy resins.