Pitch compositions for spinning into carbon articles and methods relating thereto
Pitch compositions suitable for spinning may comprise: a pitch having a softening point (SP) below 400° C. and is capable of achieving a radial Hencky strain prior to break of about 0.7 to about 10, at spinning temperature (T s ) ranging from about SP−30° C. to about SP+80° C. Methods for producing a carbon fiber from a pitch composition at a temperature within a spinning temperature (T s ) range may comprise determining a temperature range wherein the maximum radial Hencky strain (ε R ) lies above a minimum process radial Hencky strain, and wherein the minimum process radial Hencky strain is within a range of about 0.7 to about 10. The spinning temperature (T s ) range may be determined by measuring a maximum radial Hencky strain (ε R ) prior to break at a series of different temperatures and strain rates. Carbon fiber composites may comprise of the said carbon fiber.
1 . A pitch composition suitable for spinning comprising: a pitch having a softening point (SP) below 400° C. and capable of achieving a radial Hencky strain prior to break of about 0.7 to about 10, at spinning temperature ranging from about SP−30° C. to about SP+80° C., wherein the pitch has a carbon residue content ranging from about 20 wt % to about 99 wt %, based on the total weight of the pitch composition.
2 . The pitch composition of claim 1 , wherein the pitch comprises a mesophase content of about 5 vol % or less, based on the total volume of the pitch.
3 . The pitch composition of claim 1 , wherein the pitch comprises mesophase content ranging from about 5 vol % to 100 vol %, based on the total volume of the pitch.
4 . The pitch composition of claim 1 , wherein the pitch is capable of achieving an axial Hencky strain, or radial Hencky strain within the extensional strain rate ranging from about 0.1 s −1 to 100 s −1 .
5 . The pitch composition of claim 1 , wherein the pitch composition comprises a mixture of two or more pitches.
6 . The pitch composition of claim 1 , wherein the pitch has an m/z range value of about 250 to about 1,000 comprising at least 60% of pitch ion current.
7 . The pitch composition of claim 1 , wherein the pitch is an isotropic pitch having a Z number distribution (Z) in the range of about −250 to about −10.
8 . A method comprising:
producing a carbon fiber from a pitch composition at a temperature within a spinning temperature range, wherein the spinning temperature range is determined by measuring a maximum radial Hencky strain (εR) prior to break at a series of different temperatures (° C.) and strain rates (s −1 ); and
determining a temperature range wherein the maximum radial Hencky strain (εR) lies above a minimum process radial Hencky strain, and wherein the minimum process radial Hencky strain is within a range of 0.7 to 10.
9 . The method of claim 8 , further comprising: using a spinneret with a capillary size (r0) and a final fiber radius (rf), where rf is in the range of about 1 μm to about 1,000 μm, r 0 is in the range of about 100 μm to about 10,000 μm, and wherein the maximal radial Hencky strain at the spinning temperature range is at least
ε
R
=
-
2
ln
r
(
t
)
r
0
.
10 . The method of claim 8 , wherein the pitch composition comprises: a pitch having a softening point (SP) below 400° C., at spinning temperature ranging from about SP−30° C. to about SP+80° C.
11 . The method of claim 8 , wherein the pitch has a carbon residue content ranging from about 20 wt. % to about 99 wt. %, based on the total weight of the pitch composition.