Abstract

The present investigation thermoplastic blends such as polyamide66 (PA66) and polytetrafluoroethylene (PTFE)
in 80/20 weight percentage proportion was selected for the study. Three micro composites were prepared by
reinforcing fine particles (micro fillers) such as molybdenum disulfide (MoS2) PA66/PTFE/MoS2, PA66/PTFE/
MoS2/silicon carbide (SiC), and alumina (Al2O3) PA66/PTFE/MoS2/SiC/Al2O3 of different geometric shapes
to form the mixture. These hybrid micro composites were prepared by melt mixing method using twin-screw
extruder followed by injection moulding. The studied mechanical properties as per ASTM are a tensile
strength, flexural strength, and impact strength including the hardness of the blend micro composites. Results
revealed that these hybrid micro fillers decreased the tensile strength and tensile modulus of PA66/PTFE blend
composites. However, the incorporation of MoS2 into the blend increased the flexural strength and the flexural
modulus of PA66/PTFE blend appreciably, but the hybrid effect of three micro fillers decreased the flexural
strength and the modulus slightly below the value of PA66/PTFE/MoS2 composites but above the values of
PA66/PTFE blends. But, the tensile strain at break gradually decreased after the hybrid fillers addition into the
blend. The effect of SiC addition to PA66/PTFE/MoS2 composites increased the impact strength appreciably, but
decreasing trend was observed due to the hybrid effect of three fillers. However, the different shape micro fillers
exhibited a synergic effect on the tensile and flexure properties of PA66/PTFE-based composites, respectively.
The density of the studied blend increased due to denser nature of micro fillers. The hardness of the blend
increased by 3% by the addition of three micro fillers. However, the hybrid effect of micro fillers on PA66/PTFE
blend influenced the flexural properties and the hardness than tensile properties. Among these micro composites,
PA66/PTFE/MoS2 showed better mechanical properties. The fractured surfaces are studied by using scanned
electron microscopy photographs.