POLYURETHANE COMPOSITES REINFORCED BY ISOCYANATE-FUNCTIONALIZED MULTI-WALLED CARBON NANOTUBES AND CARBON NANOFIBERS

摘要

The mechanical performance of PU containing NCO-terminated multiwalled carbon nanotubes and NCO-terminated carbon nanofiber has been investigated. The addition of NCO-functionalized or unfunctionalized nano-fillers has little effect on T_g of PU. However, adding 1 % NCO-terminated and unfunctionalized carbon nanofillers greatly increase the mechanical properties of PU. For MWNT, NCO-functionalized material is less effective in enhancing the mechanical properties than the unfunctionalized material, and this is attributed to defects and tube shortening by the strong HNO_3 treatment. SEM results show that composites made with NCO-terminated MWNT has a stronger interface than composites containing unfunctionalized MWNT. For CNF, NCO functionlization appears to be more effective in improving the modulus than without functionalization. More studies are needed to explore the full potential of NCO-functionalized carbon nanofillers in polymer composites.