Enhancement of mechanical, thermal and tribological properties of AAPS-modified graphene oxide/ polyamide 6 nanocomposites

Polymer composites exploiting the outstanding properties of graphene have already attracted considerable attention. Amino-modified graphene oxide (AMG) was designed via N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AAPS) anchoring on the sheets' surfaces, as confirmed by X-ray photoelectron and fourier transform infrared spectroscopy data. It was found that the AMG had good dispersity and higher thermal stability. AMG/PA6 composites with various weight percentages of graphene platelets (0, 0.25, 0.5, 0.75, 1%) were prepared by solution blending and melting mixture. AMG markedly reduced the friction coefficient and increased the wear resistance of the polymer composites. It was shown that the friction coefficient of the AMG/PA6 composite reached 0.237, i.e., 44.6% lower than that of neat PA6, and the wear rate was decreased by 33.2%. The relations of the mechanical, thermal, tribological properties and the microstructure of the AMG/PA6 composites were also discussed. Such enhancement of tribological performance was primarily attributed to the synergistic influence of the mechanical and thermal properties of the composites and the high self-lubricity of AMG.