Modified nanosilica was prepared by esterifying nanosilica with hydoxyethyl acrylate in the presence of p-toluenesulfionic acid. Characterization of the pro ducts by Fourier transform infrared spectrometer ( FT-IR) and thermogravimetric analyzer ( TGA) showed that 70.5 % of Si-OH groups on nanosilica could esterify with hydoxyethyl acrylate. Applied in UV curable coatings

unmodified and modified nanosilica could improve the pencil hardness and abrasion resistance of the cured films

the best properties of the films was obtained when addition of nanosilica was from 4wt % to 6wt %

however

the curing rates of coatings decreased and the viscosities of coatings increased. Compared to the coatings with unmodified nanosilica

the coatings with modified nanosilica had lower viscosities

more even dispersion

faster UV curing rate and their cured films had better pencil hardness and abrasion resistance.