One-pot synthesis of aminated cellulose nanofibers by "biological grinding" for enhanced thermal conductivity nanocomposites

Abstract

Aminated cellulose nanofibers (A-CNF) with high thermostability (>350 ℃), high crystallinity (81.25 %), and high dispersion stability were extracted from "biological grinding" biomass through one-pot microwave-hydrothermal synthesis. Worm-eaten wood powder (WWP) as the product of "biological grinding" by borers is a desirable lignocellulose for fabricating A-CNF in a green and cost-effective way since it is a well-milled fine powder with dimension of dozens of microns, which can be used directly, saving energy and labor. Generated A-CNF proved to be an excellent reinforcing and curing agent for constructing high performance epoxy nanocomposites. The nanocomposites exhibited a thermal conductivity enhancement of about 120 %, coefficient of thermal expansion reduction of 78 %, and Young's modulus increase of 108 % at a low A-CNF loading of 1 wt.%, demonstrating their remarkable reinforcing potential and effective stress transfer behavior. The process proposed herein might help to bridge a closed-loop carbon cycle in the whole production-utilization of biomass.

Keywords: Aminated cellulose nanofibers; Biological grinding; Mechanochemical synergy; One-pot procedure; Thermal conductivity.