Cellulose nanowhiskers (CNWs) were prepared through a sulfuric acid hydrolysis process with cotton linter as the raw material.Then CNWs were chemically modified with dodecenyl succinic anhydride (DDSA) to obtain hydrophobic CNWs called DCNWs.The modification condition was optimized by varying the mass ratio of DDSA to CNW.The modification results were characterized by infrared spectroscopy (FTIR)

X-ray diffraction (XRD)

transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy(XPS).The DCNWs with surface substitution degree of 0.3 were chosen as fillers in the nanocomposites.Nanocomposites were prepared by incorporating different amounts of DCNW

pre-dispersed in a small amount of acetone

into an epoxy matrix.A strong interaction was observed between the DCNWs and epoxy matrix

as results of which the nanocomposites exhibited an obvious increase in Tg by about 30 K

simultaneous increases in tensile strength

Young's modulu and strain at break; and an improvement in hydrothermal properties.For example

compared with the neat epoxy

the nanocomposite containing 3.5 wt% of DCNWs exhibited an increase in tensile strength by 82%

Young's modulus by 21%

and in strain at break by 198%.The Tg value increased from 103.4 ℃ of neat epoxy to 134.1 ℃

and the water uptake decreased from 1.9% to1.4%.