Composites of polyolefin elastomer reinforced with short carbon fiber and its copolymerization conditions

To study the effects of short carbon fiber (SCF) on the properties of the polyolefin elastomers (POEs), we prepared the poly(ethylene-co-1-hexene) (PEH)/SCF composites at different percentages of SCF. We also prepared polyethylene (PE)/SCF composites to compare with PEH/SCF composites. PEH was synthesized by the copolymerization of ethylene and 1-hexene using metallocene catalyst/cocatalyst system. Optimum stirring speed, Al/Zr feeding molar ratio, polymerization time, and polymerization temperature were 700 rpm, 600, 30 min, and 60 °C, respectively. We investigated the morphology of the composites using scanning electron microscopy (SEM) and found that the wettability of SCF in PEH/SCF composites was fairly better than that of SCF in PE/SCF composites. It was observed from mechanical tests that the ultimate tensile strength and tensile modulus of PEH/SCF composites were remarkably enhanced as the SCF content increased, whereas those of PE/SCF composites were a little increased. PEH/SCF composites exhibited lower crystallinity than PE/SCF ones. Thermal stability of the composites was enhanced by the addition of SCF.