▎ 摘　　要

In this work, thermal and mechanical characterizations were performed to investigate the effect of adding 0.1 wt% of carbon nanofillers in ultra-high-molecular-weight polyethylene (UHMWPE). Two types of nanofillers were investigated: multi-walled carbon nanotubes and graphene nanosheets. The fabricated materials were evaluated through TGA and DSC techniques for thermal analyses and DMA for assessing rheological behavior, showing that the thermal resistance to degradation (T-onset) has increased by more than 20 degrees C with the incorporation of graphene fillers and around 8 degrees C with CNT comparing to the pure matrix. The main reason for the more significant increase in the thermal stability of the graphene nanocomposite was related to the 2D morphology of this type of nanocarbon particle. Moreover, the presence of only CNT increases the crystallinity degree of the composite, resulting in the storage and loss modulus increase. In addition, mechanical performance was studied through microindentation and microscratching tests, showing that the composite with CNT increased the hardness and the scratch resistance. These results were explained by the difference in the microstructure of the nanocomposites. Microscopic images obtained by SEM from the fractured surfaces of the materials revealed that graphene sheets were poorly adhered to the polymer matrix, even reducing the material's crystallinity, opposite to the nanocomposite with well-adhered nanotubes.