Environmental ageing of irradiated polypropylene/montmorillonite nanocomposites obtained in molten state

• Nanocomposites of high strength PP (HMSPP) were aged under environmental conditions.
• HMSPP/MMT nanocomposites showed carbonyl index lower than the HMSPP.
• Concentration at 0.1% of clay promoted intense crystallization of β-phase.

Nanocomposites of High Melt Strength Polypropylene (HMSPP) were obtained in organoclay concentrations of 0.1, 5 and 10 wt% using the montmorillonite (MMT). The clay was dispersed through the melting intercalation technique using a twin-screw extruder. The dumbbell samples were manufactured and settled in device for natural ageing assay. The mechanical properties (elongation and rupture strength) were evaluated and the thermal behavior was investigated by differential scanning calorimetry (DSC). The morphology of the nanocomposites was observed by scanning electron microscopy (SEM). Nanocomposites HMSPP/MMT showed intense cracks at the surface after 3 months of environmental ageing but not as deeply as in the HMSPP. The carbonyl index (CI) was calculated using infrared spectroscopy (FT-IR) technique in which the nanocomposites showed CI values lower than the HMSPP.