Effect of MWCNTs on damping behaviour of polyurethane based nano-composites

Abstract

Composites of uniformly dispersed Multi-Walled Carbon Nanotubes(MWCNTs)(1wt%) and Polyurethane(PU) were prepared by solution mixing method to fabricate disc shaped specimen with 10mm diameter and 5mm thickness. Dynamic Mechanical Analysis(DMA) testing was performed on these nano-composites by varying the loading frequency from 5 Hz to 250 Hz and storage moduli for both the compositions was obtained. It was observed that for lower loading frequency range the storage modulus for 1wt%MWCNT/PU composites increased by nearly 20% while for higher frequency loading range the increase was nearly 15%, in comparison to pure PU. In contrast, the damping factor comparison for these specimens indicated a reduction by an average of 12% signifying that presence of MWCNTs in PU composites reduces the dissipation capacity of the composite material. Such composite materials, possess wide variety of engineering applications wherein damage and fracture needs to be reduced by fabricating more elastic materials having higher storage energy capacity.