Preparation of high impact polystyrene/carbon black/coir fiber composites for electronic packaging application

Abstract

This research focused on the preparation of conductive composites for utilizing in the electronic packaging applications between coir fibers and high impact polystyrene (HIPS)/carbon black (CB) composites by varying contents of CB at 1-9 phr and coir filler at 1-15 phr. The composites were prepared by mixing the constituents and fabricating using a twin screw extruder and compression molding, respectively. Experimental results reveal that for HIPS/CB composites, CB loading of 5 phr was the lowest amount which can change the conductive properties of the composite from an insulator to a conductor which had the surface resistivity equal to 1.20x10[superscript 7] ohm/square. The conductive properties of this composite resulted from the accumulation of CB particles in form of the CB agglomerates and aggregate chains that tended to flocculate and link together into network structure within the polymer matrix. The network structure facilitated movement of electrons through the polymer matrix. For mechanical properties, the addition of CB enhanced the modulus, tensile strength, and flexural strength of the composites whereas impact strength decreased. In case of HIPS/CB/coir filler composites, the addition of insulating coir filler did not cause an increase in the surface resistivity of the composites because of the composites because of the polarity effect of coir filler that can induce the cluster of CB to form network structure on the fiber surface. In addition, the addition of coir filler loading, in particular at 5-9 phr, tended to decrease the surface resistivity of the composites gradually. For mechanical properties, the addition of coir filler enhanced the modulus of the composites, while the tensile strength and flexural strength were closed to HIPS/5CB composite and the impact strength decreased. In conclusion, the HIPS/CB (5phr)/coir filler (9 phr) composite showed suitable mechanical properties and had the lowest resistivity (4.15x10[superscript 5] ohm/square).