Enhanced Mechanical Toughness of Isotactic Polypropylene Using Bulk Molybdenum Disulfide

Herein, we report the use of bulk molybdenum disulfide (MoS₂) as the reinforcing agent to enhance the toughness of isotactic polypropylene (iPP). The iPP-MoS₂ nanocomposites with varying amounts of MoS₂ (0.1 to 5 wt %) were prepared by a one-step melt extrusion method, and the effects of MoS₂ on the morphology, thermal, and mechanical properties were evaluated by different instrumental techniques such as Raman, ATR-FTIR, UTM, TEM, TGA, and DSC. TEM images showed the uniform dispersion of multilayer MoS₂ in the polymer matrix, and XRD results suggested the formation of the β phase when a low amount of MoS₂ is loaded in the composites. Mechanical tests revealed a significant increase in the toughness and elongation at break (300-400%) in the composites containing low amounts of MoS₂ (0.25 to 0.5 wt %). Enhanced toughness and elongation in iPP could be related to the combined effect of the β phase and the exfoliation of bulk MoS₂ under applied stress. The thermal stability of the composites was also improved with the increase in MoS₂ loading. Direct utilization of bulk MoS₂ and one-step melt extrusion process could be a cost-effective method to induce high elasticity and toughness in iPP.