Surface property effects of compounding a nanoclay masterbatch in PP injection moulding

V. PETTARÍN; L. A. FASCE; M. S. CORREIA; A. J. PONTES; J. C. VIANA; P. M. FRONTINI; A. S. POUZADA

Ghent

Conferencia; 4th International Conference PMI2010; 2010

University College Ghent

The interest on the use of nanofillers in injection mouldings has been going on for more than adecade but a real breakthrough has not been achieved yet, especially in that mechanical properties are concerned. The nucleating effect of nanoclays in semicrystalline polymers suggests that surface effects may result interesting especially during processing. This paper includes some information on the surface properties of an injection moulding grade of polypropylene mixed with a commercial masterbatch of PP and 50% of organoclay. They were moulded as plates for testing in a prototype device for determining the coefficient of friction in as-moulding conditions. The surface was also characterised by depth sensing indentation tests. The through thickness microstructures of the mouldings were assessed by optical microscopy and differentialscanning calorimetry, while surface morphology was assessed by X-ray diffraction. It was observed that independently of MB content, its addition caused a slight increase in elastic modulus and hardnessin the skin layer.The friction properties directly associable to the product performance showed a slight improvement interms of the dynamic friction coefficient. Conversely the static friction coefficient that is relevant inprocessing was no affected by the presence of the nanoclay.