Process for preparing a carbon fiber precursor

A carbon fiber prepared according to the process of:

• (a) obtaining a series of monomer mixtures, wherein each mixture of monomers includes acrylonitrile and an ammonium salt of 2-acrylamido-2-methyl propane sulfonic acid;
• (b) individually polymerizing the monomer mixtures to obtain a PAN polymer;
• (c) individually spinning the PAN polymer to obtain PAN filaments;
• (d) individually bundling the filaments to obtain a PAN fiber;
• (e) individually analyzing the PAN fiber for a physical property, wherein the property is a member selected from the group consisting of:
• number of surface defects, interior homogeneity, degree of orientation, tenacity, number and size of micro voids, arrangement of crystallites on the surface, compactness of structure, and combinations thereof;
• (f) ranking the PAN fiber, wherein a most highly ranked solid PAN fiber is the carbon fiber precursor;
• (g) heating the carbon fiber precursor in a first heating step to obtain PANOX fiber;
• and
• (h) heating the PANOX fiber in a second heating step to obtain carbon fiber.

An apparatus for preparing a carbon fiber precursor, the apparatus comprising:

• (a) a polymerization zone for obtaining a series of solid PAN polymers, wherein each solid PAN polymer in the series contains a different ratio of monomers, and wherein the monomers are acrylonitrile and an ammonium salt of 2-acrylamido-2-methyl propane sulfonic acid;
• (b) a first transfer means for removing the PAN polymer to a spinning zone;
• (c) a spinning zone for obtaining PAN filaments:
• (d) a second transfer means for removing the PAN filaments to a bundling zone;
• (e) a bundling zone for obtaining PAN fiber;
• (f) a third transfer means for removing the PAN fiber to an analysis zone;
• (g) an analysis zone, wherein the analysis zone includes measurement devices for obtaining a physical property of the PAN fiber, and wherein the physical property is a member selected from the group consisting of:
• number of surface defects, interior homogeneity, degree of orientation, tenacity, number and size of micro-voids, arrangement of crystallites on the surface of the fiber, compactness of structure and combinations thereof;
• and
• (h) a ranking zone, wherein a most highly ranked PAN fiber is the carbon fiber precursor.

A mixture of monomers useful in preparing a carbon fiber precursor, wherein the mixture is obtained from a process comprising:

• obtaining a series of monomer mixtures, wherein the monomer mixtures comprise acrylonitrile in an amount of about 92 mole % to about 99.5 mole % and an ammonium salt of 2-acrylamido-2-methyl propane sulfonic acid in an amount of about 0.5 mole % to about 8 mole %;
• polymerizing the monomer mixtures to obtain a series of PAN polymers;
• spinning the PAN polymers to obtain a series of PAN fibers;
• analyzing the series of PAN fibers to obtain a set of analysis results, wherein a physical property of the PAN fibers is analyzed, wherein the property is a member selected from the group consisting of:
• number of surface defects, interior homogeneity, degree of orientation, tenacity, number and size of micro voids, arrangement of crystallites on the surface, compactness of structure, and combinations thereof;
• and
• ranking the PAN fibers based on the set of analysis results;
• and wherein the mixture of monomers yielding the most highly ranked PAN fiber is employed as starting material for the preparation of the carbon fiber precursor.