Study on Effect of Master Batch on the Physical Properties of PP/MWCNT Nanocomposites

Abstract

Effect of masterbatch (MB) on the properties of polypropylene/multi-walled carbon nanotube (PP/MWCNT) nanocomposites was studied. Nanocomposites with same compositions but different fabrication protocols were compared. In one-step mixing protocol, PP and MWCNT were compounded at once. In two-step mixing protocol, MB was first prepared from PP and high concentration of MWCNT and followed by subsequent dilution process with additional PP and MB. It was found that two-step protocol using MB enhanced the dispersion of MWCNTs and consequently mechanical and electrical properties were improved. When the MB was fabricated by PP, MWCNT and polypropylene-g-maleic anhydride (PP-g-MA), the properties of resulting nanocomposites were higher than those without PP-g-MA. This is attributed to increased affinity between matrix polymer and MWCNT due to the increased polarity of matrix polymer by incorporation of PP-g-MA. When PP of lower viscosity was used for the MB, the dispersion of MWCNT was much enhanced and the mechanical and electrical properties were also increased.