Influence of twin-screw configuration on the mechanical and morphological properties of polypropylene-clay composites

The influence of eight different twin-screw configurations, mainly varying in arrangement of restrictive (negative) kneading elements, on the mechanical and morphological properties of composites of polypropylene (PP) reinforced with organic modified montmorillonite (MMT) and coupling agent polypropylene-grafted-maleic anhydride (PP-g-MA) was studied. Pressure profile, maximum strain, fill rate and average viscosity were calculated using an existing twin-screw modelling software. Impact and tensile tests results, scanning electron microscopy (SEM) images and X-ray diffraction (XRD) measurements of the composites showed no significant influence of the position of the negative kneading blocks.