EFFECT OF LONG-CHAIN ALKYLAMINE ON THE DISPERSIBILITY AND TRIBOLOGICAL PROPERTIES OF ALKYL-GRAPHENE IN LUBRICANT OIL

We report on the preparation of Alkyl-Graphene by hydrothermal method, and their dispersion in lubrication oil. The alkylated graphenes with variable alkyl chain lengths (C n = 8, 12, 18) are prepared by coupling of alkylamine with carboxylic groups of graphene oxide (GO). FTIR, XPS, TGA methods were used to analyze and assess the GO modified ability by amine. The morphology and microstructure of prepared GO and alkyl-graphene were examined using field emission scanning electron microscopy (FESEM), transmission electron microscopy (HRTEM), X-ray diffraction (XRD). The experiments confirmed the formation of GO and alkyl-graphene. Stably distributed system of alkyl-graphene in SN500 reached 13.2 g/l with octylamine and 9.5 g/l with decylamine and 6.0 g/l with dodecylamine. The lubricating characteristics of lubrication oil containing alkyl-graphene was determined according to ASTM D2783. Evaluation of the reduction performance of SN500 oil when adding with alkyl-graphene: modified GO by octylamine gave the best performance compared to decylamine, dodecylamine. The reduction of abrasion reached 11.3 % at 0.3 g/l and 12.5% at 0.4 g/l of octyl-graphene.