HYBRID POLYETHYLENE COMPOSITES FOR ROTATIONAL MOULDING: INCORPORATION OF WOLLASTONITE MINERAL FIBRES, SISAL FIBRES AND COUPLING AGENT

摘要

A new charge material for rotational moulding involving polyethylene (PE), wollastonite mineral microfibres, short sisal fibres and maleated polyethylene (MAPE) as the coupling agent has been developed. Wollastonite, sisal fibres and PE are premixed by blending and compounding with a single screw extruder and then granulated to particles with diameter about 0.5 mm prior to rotational moulding, for which the mixture is placed in a mould that is heated from the outside to 250 deg C for a period of about 10 minutes. The properties of the resulting composites are characterised by tensile strength, tensile modulus and impact strength measurements that show mixed results. Incorporation of fibres without any coupling agent improves the tensile strength associated with a reduction in impact strength. Addition of a coupling agent improves the mechanical performance and the processability. Scanning electron microscopy reveals good adhesion between the fibre reinforcement and polyethylene matrix at the fracture surface.