A. Kaynak et al., SOME MICROWAVE AND MECHANICAL-PROPERTIES OF CARBON FIBER-POLYPROPYLENE AND CARBON BLACK-POLYPROPYLENE COMPOSITES, Materials research bulletin, 31(10), 1996, pp. 1195-1206
The insertion loss, return loss and electromagnetic shielding effectiv
eness of carbon-black and carbon-fiber-filled polypropylene composites
were studied in the 8 to 12 GHz frequency range. Both electromagnetic
and mechanical measurements were performed at various filler concentr
ations. The maximum shielding values obtained for carbon-fiber-filled
composites was over 40 dB for 35 wt% concentration. Young's modulus, u
ltimate strength and elongation at break with respect to filler concen
tration were also determined. The stiffness and brittleness of the com
posites increased with increasing filler concentration. The ultimate s
trength of the carbon-black-filled composites increased whereas the ul
timate strength of carbon-fiber-filled composites decreased with the f
iller content. Elongation at break values for all composites dropped s
harply with the filler concentration.