Flammability, structure and mechanical properties of PP/OMMT nanocomposites

Abstract

Polypropylene/organoclay (PP/OMMT) nanocomposites were prepared in a twin-screw corotating extruder using two methods. The first method was the dilution of commercial (PP/50% Nanofil SE3000) masterbatch in PP (or PP with commercial flame retardant). The second method consists of two stages was the extrusion of maleic anhydride grafted polypropylene (PP-g-MAH) with commercially available organobentonite masterbatch in first stage and dilution of the masterbatch in PP (or PP with commercial flame retardant) in second stage. XRD results showed no intercalation in composites obtained from commercial masterbatch without compatibilizer and semi – delamination for compatibilized systems. Tensile tests revealed that nanocomposites with 5% of organoclay have a slightly higher tensile modulus and tensile strength than pristine PP, however addition of the commercial flame retardant (FR) reduces mechanical parameters to roughly the level of those for neat PP. PP/OMMT composites have approx. 25% higher oxygen index than pristine PP, and this changes slightly after the addition of FR. The cone calorimeter tests showed a decrease of a heat release rate (HRR) and a mass loss rate (MLR) after the addition of FR.