Abstract:
The graphene oxide (GO) synthesized by Hummers' method was mixed into coupled product nano SiO
2-NH
2 obtained by silane coupling agent (APTES) modifying nano SiO
2 to prepare nano SiO
2 functionally modified graphene sheet composites (nano SiO
2-g-GS) through the graphene sheets grafting with nano SiO
2. The nano SiO
2 functionally modified graphene/thermoplastic polyurethane composites (nano SiO
2-g-GS/TPU) were fabricated by melt compounding method using the thermoplastic polyurethane (TPU) as the matrix and nano SiO
2-g-GS as the filler, and then the fillers and composites were systematically characterized. The tensile tests show that the stress at definite elongation (300%, 500%, 1 000%) of nano SiO
2-g-GS/TPU composites increases due to nano SiO
2-g-GS has strengthening effects on the TPU. DSC tests show that the crystallinity temperature of the nano SiO
2-g-GS/TPU composites increases significantly compared with pure TPU, and the crystallinity temperature of TPU with 1wt% mass fraction of nano SiO
2-g-GS increases by 44℃. The shape memory testing results show that the shape recovery ratio (
Rr) of nano SiO
2-g-GS/TPU decreases and the shape fixing ratio (
Rf) increases with the increase of the mass fraction of nano SiO
2-g-GS. The nano SiO
2-g-GS/TPU composites with 1 wt% nano SiO
2-g-GS exhibit the best performance.