| 초록 |
In this study branched polyethyleneimine (b-PEI)-assisted exfoliation of MoS2 nanosheets (MoS2¬-PEI) was carried out. These non-covalently functionalized MoS2-PEI nanosheets were employed as toughening agents for epoxy composites. The contents of MoS2-PEI nanosheets were maintained at weight fractions lower than 0.16 wt%. The epoxy composites exhibited a 67% increase in fracture toughness (KIC) and a corresponding 101% increase in fracture energy (GIC) at nanosheets loadings as small as 0.06wt.% (MP-6), KIC shows linear relationship with the surface free energy (SFE) and is highest at 81 mJ m−2 for the MP-6 composite. However, the SFE values of the MP-9 and MP-16 composites decreased to 67.20 mJ/m2 and 70.25 mJ m−2. Furthermore, the thermal stability of the epoxy composites improved significantly. The optimum MoS2-PEI nanosheet loading was observed to be 0.06wt.%, beyond which a gradual decrease in the thermal stability was observed. |
