This paper is focusing on the physical and mechanical properties of polyolefin/nano clay
composites. The samples used in this work were prepared through melt compounding, using
high-density polyethylene (HDPE) and polypropylene (PP) doped with clay of montmorillonite
(MMT). During the preparing of HDPE/MMT or PP/MMT nanocomposites, Dioctyl phthalate
(DOP) as a plasticizer and stearic acid as lubricant were added. Different concentration of MMT
in PE and PP composites were prepared at 1 wt% to 5wt% by using a Plastograph-Mixer through
twin-screw extruder. XRD examination did not show any change in the degree of crystallinity for
HDPE/MMT but for PP/MMT indicates the formation of α or β peaks. It's found that the MMT
nano-particles have a good dispersion inside the polymer matrix as examined by using SEM. By
using the DSC, it is found that there is no significant change in the melting point of the prepared
samples. On other hand, the thermal stability decreased by increasing the MMT concentration in
the PE/clay and PP/clay nanocomposites, as seen from TGA examination. The mechanical
properties have been improved by adding MMT nano-particles inside the PE and PP matrix.
Both the modulus of elasticity ( ) and the maximum stress ( ) of PE/MMT is found to have a
peak value at 2 wt%, while it was at 3 wt% for PP/MMT.