Effect of MMT concentrations as reinforcement on the properties of recycled PET/HDPE nanocomposites

Abstract

Abstract The objective of this research is to investigate the effect of incorporating montmorillonite (MMT) on the mechanical, morphological, rheological, and thermal properties of recycled poly(ethylene terephthalate) (rPET) and high-density polyethylene (HDPE) nanocomposites. The MMT contents in 90:10 rPET/HDPE and 70:30 rPET/HDPE ranged from 1 to 5 wt.%. rPET/HDPE nanocomposites were prepared by using a single screw extruder, and injection molded to prepare mechanical test specimens. The samples underwent rheological tests by using a capillary rheometer, and the morphology of the nanocomposites was investigated by scanning electron microscopy (SEM). The thermal stability of the nanocomposites was tested using thermogravimetric analysis (TGA). The results showed that MMT acts as compatibilizing agent and improves phase dispersion and interfacial adhesion in the nanocomposites. The maximum tensile strength was found at 3 and 1 wt.% of MMT for the 90:10 and 70:30 rPET/HDPE blends. However, the tensile modulus decreased significantly with the incorporation of MMT. The impact strength for both the 90:10 and 70:30 blends reached a maximum at 3 wt.% and started to decrease beyond 3 wt.%. The incorporation of MMT increased the shear viscosity of the 90:10 and 70:30 blends, which reached a maximum value at 3 and 1 wt.%. SEM micrographs showed a good interaction of MMT that improved the adhesion between the two phases of blends and led to an increase in the mechanical properties of rPET/HDPE nanocomposites.