Analysis of young's modulus of polypropylene/clay nanocomposites

Abstract

This work aimed to study the effects of the contents of Polypropylene-grafted-Maleic Anhydride (PP-g-MA) compatibilizer and organo-modified Montmorillonite clay (Org-MMT) nanofiller on the Young's Modulus of Polypropylene/Montmorillonite Clay Nanocomposites and to study the mechanisms of reinforcement of nanocomposites based on Rules of Mixture (ROM), Inverse Rule of Mixture (IROM), and Halpin-Tsai models. The PP/PP-g-MA/Org-MMT nanocomposites were melt-mixed in the twin-screw extruder. The dry extruded pellets were injection molded into the standard tensile bar for the tensile strength measurement with the universal testing machine (INSTRON). The gallery spacing of clay platelets were determined by X-ray Diffraction Transmission Electron Microscopy was used to study the morphology of the nanocomposites. The experimental results showed that the 9 wt% PP-g-MA was the maximum loading for adhesion enhancement between PP and Org-MMT. The PP/PP-g-MA/Org-MMT nanocomposites prepared were mainly the intercalated nanocomposites. The clay gallery spacing increased from 3.05 to 3.27 nm. The Young's modulus of PP/PP-g-MA/Org-MMT at 9 wt% PP-g-MA increased from 1.10 to 1.54 Gpa with the increase of the inorganic MMT content from 0 to 3.33 wt% partly due to the acute orientation angle of clay platelets in the polymer matrix. The Halpin-Tsai model could predict the Young's modulus of the nanocomposites providing that the accurate filler aspect ratio and filler orientation can be obtained.