Synthesis and Characterization of LDPE-Carbon Nanotube Composite Foams

This study details the synthesis and characterization of composites and composite foams of low-density polyethylene (LDPE) and multi-walled carbon nanotubes (MWCNT). LDPE-MWCNT composites were prepared by melt blending the components in a twin screw compounder and their foams were produced by batch foaming using CO₂ as the blowing agent. The composites were characterized for dispersion using SEM and image results indicate good dispersability of MWCNT in LDPE with the formation of a MWCNT network in the LDPE matrix. Thermal and rheological properties of the composites were characterized and results indicate that even a small amount (1 wt.%) of MWCNTs can significantly affect the crystallization kinetics and the rheological behavior. Batch foaming results of the composites depict MWCNTs as heterogeneous nucleation sites for gas bubbles as indicated by the increase in cell density of the composite foams when compared to LDPE foams.