Covalent functionalisation by cycloaddition reaction of pristine graphene based on Diels–Alder chemistry and its reinforcement for polyamide 66 fibres

A solvent-free and easy method to directly functionalize pristine graphene by maleic anhydride (MA) based on Diels-Alder cycloaddition reaction was reported. Functionalized graphene/Polyamide 66 (FGN/PA66) composite fibers were fabricated by melt-spinning as a potential industrial application. The results show that the functionalized graphene has compatibilized the interface and increased the dispersibility in the PA66 matrix, which leads to an improvement in mechanical properties. When the content of filler was 0.2 wt%, the fracture strength of graphene/PA66 and FGN/PA66 composite fibers reached the maximum value of 584 MPa and 678 MPa, respectively, which were 88.4% and 118.8% higher than that of pure PA66 fiber. It's believed the functionalized graphene will facilitate the industrial scale fabrication of graphene based composite and the FGN/PA66 composite fibers with higher mechanical properties will expand the application of PA66.