Cashew Nut Shell Liquid (CNSL)-Derived Epoxy Composite Reinforced by Cellulose Nanofiber

Abstract

Bio-based epoxy polymers consisting of cashew nut shell liquid (CNSL)-derived epoxy cardanol prepolymer (ECP) and phenalkamine were reinforced using two types of cellulose nanofibers (CNFs) with different hydrophobicity. The more hydrophobic CNF(A) chemically bonded with phenalkamine improved the mechanical and thermal properties of the composites. The composites at a CNF content of 2.0 wt% had the tensile strength and Young’s modulus of 85 and 500 MPa, respectively, which were 2.9 and 9.4 times greater than those of the base epoxy resin, respectively. Thus, CNSL-based epoxy composites effectively reinforced with hydrophobic CNFs promising high potential as a bio-based epoxy coating, film, and resin.