▎ 摘　　要

The reduction extent of graphene oxide (GO) was tailored by adjusting the solvothermal reduction time. The effects of the reduction extent of GO on the structure and properties of graphene/poly(vinyl alcohol) (PVA) composites were investigated. Results show that the mechanical properties of polymer composites are sensitive to the reduction extent of GO, and reduced graphene oxide (rGO) with an optimum reduction extent (C/O ratio = 3.94) could more efficiently improve the mechanical properties of PVA than low/high reduction extent rGO. Low reduction extent rGO could enhance the interfacial interactions through the formation of hydrogen bonds with PVA chains, but its mechanical strength is smaller. High reduction extent rGO has stronger mechanical strength while the deep deoxidation of GO significantly weakens interfacial interactions between rGO nanosheets and PVA chains. Achieving optimum reinforcing effects requires balancing and optimizing interfacial interactions and mechanical strength of rGO.