Evaluating Storage and Effective Moduli of In Situ Polymerised and Melt Extruded PA6 Graphite (G) Composites.

Abstract

Four PA6/graphite (G) composites systems were made. Two using in situ polymerisation equivalent in mixing strain and two systems melt extrusion of equivalent processing strain. The effective modulus of the carbons, room temperature storage modulus and storage modulus at 80⁰C were evaluated. The composite/unfilled PA6 ratios at E25 and that at E80 for the in situ polymerised system IG 40/10 are 1.37 and 1.63, respectively. For the in situ polymerised system IG 20/20, the same were 1.96 and 2.28, respectively. For the melt-extruded systems, G 100/6 had the best E25 ratio of 1.67 and E80 of 2.03, whereas the same for G 200/3 system were respectively 1.87 and 2.64. While the better storage modulus properties exhibited by IG 20/20 in the in situ polymerised system is associated with a better filler connectivity network that enhanced heat dissipation. The better values shown in the G 200/3 melt-extruded system is associated with the lesser extrusion, which significantly reduced the tendency to thermal decay. Effective modulus for the in situ polymerised systems IG 40/10 and IG 20/20 were 7.5GPa and 8.9GPa while that of melt-extruded systems G200/3 and G100/6 tallied at 8.2 GPa.

Keywords

• effective-modulus, in situ-polymerisation, melt-extrusion, storage-modulus