▎ 摘　　要

Graphene oxide (GO) can improve the mechanical property of polymer matrix greatly. However, its poor dispersibility may considerably lower reinforcing efficiency. To address this problem, the environment-friendly polyaspartic acid (PASP) was adopted to modify GO through two generally modified methods: hydrogen bond adsorption and chemical graft modification. Findings indicate that the covalent bond grafted PASP-GO exhibits better dispersibility than the product by noncovalent method (PASP/GO-noncovalent). For chemically grafted PASP-GO, the nearly spherical polymer nanoparticles are formed on the GO nanosheets through self-polymerization, and its size can be well manipulated by adjusting the dosage of PASP so as to yield PASP-GO-1/4, PASP-GO-1/2, and PASP-GO-1/1 (mass ratio: m(PASP)/m(GO) = 1/4, 1/2, and 1/1); the corresponding diameters of these polymer aggregates are 56.4 +/- 7.1, 90.1 +/- 12.6, and 151.2 +/- 16.1 nm. They are further utilized to reinforce polyimide matrix. Compared with the PASP-GO-1/2 and PASP-GO-1/1, the smaller PASP-GO-1/4 has better strengthening effect, due to its high specific surface area and dense distribution. This desirable fabrication of GO-based nanofillers provides a new avenue on the development of polymer matrix with comprehensive performances. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47939.