Influence of the graphite type in the mechanical properties of graphene nanosheets and ultra high molecular weight polyethylene (GN/UHMWPE) nanocomposites

This paper studies the mechanical properties of graphene nanosheets and ultra high molecular weight polyethylene (GN/UHMWPE) nanocomposites. The graphene nanosheets were obtained by two methods: the first, from Graphite Micrograf HC11 after 8 hours in a ultrasound bath in 70% alcoholic solution; the second, from Graflake 9950 prepared by oxidizing with H₂SO₄/HNO₃ (4:1), followed by thermal expansion at 1050°C for 30 seconds and ultrasound bath for 20 hours. Both were oven dried for 24 hours at 110°C and subsequently added to the polymer in percentages of 0.5, 1.0 and 1.5% (w/w). The powders of the nanocomposites were mixed in a ball mill for 1 hour and molded by hot compression. XRD and SEM images was possible to verify that the Graflake's GN had higher delamination that the Micrograph's GN. The mechanical properties were affected in different percentages for each graphite type. (author)