Mechanical Analysis of Carbon Nanofiber/Epoxy Resin Composites

摘要

The mechanical response of epoxy resins filled without treated carbon nanofibers and carboxylated ones has been evaluated through tensile tests. The elastic properties did not improve compared to the neat epoxy resin regardless of filler content or functionalization treatment, while the tensile strength and the elongation at break were reduced for the highest filler content (1 wt%). Fractographic analysis showed that composites reinforced with carboxylated nanofibers showed better filler dispersion than those without treatment. However, in both cases, the fibers tended to agglomerate and the formation of porosity was favored. The size of bundles of nanofibers rose with the content of nanofiller and for the same addition of carbon nanofibers, the size and distribution was respectively bigger and wider for the untreated carbon nanofibers-reinforced composites than for the carboxylated carbon nanofiber-rein-forced composites. These defects degraded the mechanical response. The dilute suspension of clusters model was applied to estimate the elastic properties, showing agreement with the experimental results.