Study on the effect of tailoring the hard copolymer polyurethane on the thermal, mechanical and electrical properties of hard copolymer polyurethane/multi-walled carbon nanotubes nanocomposites

Abstract

This study focusses on the effect of the addition of multi-walled carbon nanotubes (MWCNTs) on the morphology and thermal, rheological and electrical properties of hard copolymer polyurethane (HCPU) using 1,5 pentane-diols as a chain extender, containing 85% of hard segment blocks. Step-growth polymerisation was used to synthesise a HCPU polymer matrix, followed by melt compounding to prepare the nanocomposites. SEM investigation of the neat HCPU structure and its nanocomposites indicated the uniform dispersion of MWCNTs within the polymer matrix; further TEM morphology investigation showed some agglomeration regions, attributed to the high MWCNT content (2 wt%). An XRD test confirmed a homogeneous distribution of MWCNTs by observing the remaining location of the highest peaks of MWCNTs and amorphous peaks of the HCPU matrix. Analysis of the melt rheology test results showed an improvement in complex viscosity combined with an increase in the G’ and G” of nanocomposites from those of pure HCPU due to the presence of MWCNTs. Finally, electrical conductivity of nanocomposites demonstrated a significant improvement in its value at high loading of MWCNTs from that of pure HCPU matrix.