Their extremely high thermal conductivity, combined with their relativ
ely low density, make mesophase pitch-based carbon fibers attractive f
or many applications where heat transfer is critical. Although many th
ermal management applications could create large markets for mesophase
fibers, the current high cost of these fibers makes their use unecono
mical. The objective of the present research is to produce low-cost, m
esophase pitch-based carbon fibers with high mechanical and thermal pr
operties. In the current study, circular and ribbon fibers were produc
ed from a naphthalene-based mesophase. After stabilization and carboni
zation, their mechanical and electrical properties were compared to fi
bers produced at similar conditions, but using a heat-soaked mesophase
precursor. The ribbon fibers produced from the naphthalene-based meso
phase exhibited higher moduli and electrical resistivities than round
fibers formed from the same precursor. Also, the mechanical and electr
ical properties of the naphthalene-based ribbon fibers were superior t
o ribbon fibers previously produced using a heat-soaked mesophase and
heat treated at equivalent conditions. At carbonization temperatures o
f only 2250-degrees-C, the ribbon fibers produced from naphthalene-bas
ed mesophase developed electrical resistivities as low as 2.68 muohm .
m, a factor of three lower than those previously produced from the he
at-soaked mesophase. Thus, ribbon fibers formed from naphthalene-based
mesophase should exhibit higher thermal conductivities than either ro
und fibers formed from the same precursor or ribbon fibers formed from
a heat-soaked precursor. An additional benefit is that fibers formed
from naphthalene-based mesophase develop excellent properties at relat
ively low carbonization temperatures.