Abstract:

Cellulose nanofibers （CNF） were prepared using wood powders as a raw material， and then the epoxy （EP）⁃based composites with the glycidyl methacrylate （GMA）⁃modified CNF were prepared using a solution casting method. The effect of CNF and GMA contents on the properties and mechanisms of the composites were investigated through characterizing their mechanical properties， light transmission properties， hydrophilic properties， thermal stability， and microstructure. The results indicated that the EP/CNF composites exhibited an increase at first and then a decrease in tensile strength， elongation at break， and light transmittance with an increase in the CNF content， and their hydrophilic property increased with the CNF content. The EP/CNF composites obtained optimal performance at a CNF content of 0.6 wt%， resulting in tensile strength of 32.166 MPa， elongation at break of 20.995 %， and light transmittance of 79.8 % at 600 nm， and a contact angle of 77.34°. The compatibility between the GMA⁃modified CNF and EP was improved， leading to an enhancement in the mechanical properties and thermal stability of the composites. Their tensile strength， elongation at break， light transmittance， and hydrophilic property varied with an increase in the GMA content. The EP/GMA⁃modified CNF composites exhibited optimal performance at a GMA content of 4.8 wt%， resulting in tensile strength of 57.933 MPa， elongation at break of 18.762 %， light transmittance of 86.3 % at 600 nm， and a contact angle of 81.42°.

Key words: cellulose nanofiber, epoxy resin, glycidyl methacrylate, composite