Effect of functionalized MWCNTs on the thermo-mechanical properties of poly(5-ethylidene-2-norbornene) composites produced by ring-opening metathesis polymerization

Functionalized multiwalled carbon nanotubes (MWCNTs) reinforced poly(5-ethylidene-2-norbornene (ENB)) composites have been fabricated via ring-opening metathesis polymerization. Verification of covalent bond formation between the functionalized carbon nanotubes and the polyENB matrix was demonstrated by solvent exposure followed by thermal gravimetry. The tensile toughness of the composites increased by 300% with dramatic morphological changes on the resulting fracture surfaces when just 0.8 wt% norbornene-functionalized MWCNTs (f-MWCNTs) were added to the polymer. A slight increase of glass-transition temperature was observed by dynamic mechanical analysis compared to a decreased value with unfunctionalized MWCNTs.