▎ 摘　　要

Inspired by the strengthening effect of nanoparticles and the toughening effect of block polymers, we prepared a block polymer filler with graphene oxide (GO) as the main body by surface initiate atom transfer radical polymerization (SI-ATRP). In the side groups of the main molecular segment of this block polymer, glycidyl methacrylate (GMA) fragment and N-(3,4-bis([tert-butyldimethylsilyl]oxy)phenethyl)methacrylamide (DOPAmTBDMS) fragment can promote dispersion and toughening respectively. The molecular structure was characterized by Fourier transform infrared and X-ray photoelectron spectroscopy. After the modified GO was added to the epoxy composite, the mechanical properties of the composite could be significantly improved. The toughness of epoxy composites was enhanced by crack deflection of the matrix. When the added amount of modified GO was 0.25 wt%, the flexural strength reached 151 MPa, which was 37.27% higher than pure epoxy composite. The tensile strength and izod impact strength were increased by 50.56% and 69.89%, respectively. These are attributed to the strengthening and toughening effects of GO and the side groups on it. This research had potential application value in the field of resin fillers and in combination with carbon fiber, metal and other materials.