Improvement of impact strength of CFRP by using cellulose nano fiber without hydrophobic treatment

Abstract

Carbon fiber reinforced plastics (CFRP) has high strength and light weight properties. However, for impact load, an improvement has been required since resin matrix is weak. For CFRP manufacturing, the authors have developed the electro-activated deposition resin molding (EDRM) method to impregnate the resin, and the strength of CFRP for the static load was increased by the application of CNF without hydrophobic treatment. In this study, applying EDRM method, the impact strength of CFRP was improved by using cellulose nanofiber (CNF) without hydrophobic treatment. The electro-activated deposition solution contains polymer with epoxy group. The method was to apply the mixture of CNF dispersion and electro-activated deposition solution to the prepreg. After thermal curing, the CFRP which has CNF layer on the surface was obtained. The three-point bending test was carried out to confirm the static strength, and the impact strength was also confirmed by the Charpy impact testing.