Interfacial and mechanical properties of epoxy composites containing carbon nanotubes grafted with alkyl chains of different length

Abstract

Dispersion of the nano-fillers is important in the manufacture of high performance nanocomposites. Dispersion of silane treated CNT/epoxy composites was analyzed for various alkyl chain lengths. Difference in mobility of alkyl chains of different length affects the excluded free volume and repulsive forces. An optimal chain length was observed to impart maximum mechanical and impact properties. Differences in the dispersion of CNT due to alterations in alkyl chain lengths were determined using electrical resistance measurement. Spreading of CNT/epoxy rearranged the CF tow resulting in a change in electrical resistance ratio (CERR) and the differences in alkyl chain length effected CNT spreading. Dispersion and wetting conditions with different alkyl chain lengths resulted in changes in CERR, ILSS and other proprieties. The butyl chain length was optimal of the alkyl chain lengths studied. This is attributed to the butyl chains known good mobility and steric repulsion effects compared to longer alkyl chain lengths.