Method for the preparation of carbon fiber from polyolefin fiber precursor, and carbon fibers made thereby
AssigneeUT-Battelle, LLC
InventorsAmit Kumar Naskar, Marcus Andrew Hunt, Tomonori Saito
Life of this patent
Estimating the term…
Abstract
Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.
Claims25
A method for the preparation of carbon fiber from polyolefin fiber precursor, the method comprising partially sulfonating said polyolefin fiber precursor to produce a partially sulfonated polyolefin fiber, and subjecting said partially sulfonated polyolefin fiber to carbonization conditions to produce said carbon fiber, wherein partial sulfonation of said polyolefin precursor fiber produces a surface-sulfonated polyolefin fiber by sulfonating a surface layer of said polyolefin fiber precursor while leaving a core portion of said polyolefin fiber precursor unsulfonated, wherein subsequent carbonization volatilizes the unsulfonated core portion and carbonizes the surface-sulfonated portion to produce a hollow carbon fiber.
A method for the preparation of carbon fiber from polyolefin fiber precursor, the method comprising partially sulfonating said polyolefin fiber precursor to produce a partially sulfonated polyolefin fiber, and subjecting said partially sulfonated polyolefin fiber to carbonization conditions to produce said carbon fiber, wherein partial sulfonation of said polyolefin fiber precursor is accomplished by melt mixing polyolefin precursor resin with a sulfonated material to produce a melt-mixed composite, spinning the melt-mixed composite to produce a melt-mixed composite fiber, followed by subjecting the melt-mixed composite fiber to a desulfonation temperature of at least 50° C. and below a carbonization temperature under a nominal applied stress along the fiber length to avoid fiber shrinkage.
A method for producing a hollow carbon fiber, the method comprising subjecting a multi-component polymer fiber composite to a carbonization step, wherein said multi-component polymer fiber composite is comprised of a sulfonated outer layer and an unsulfonated core, wherein said unsulfonated core is volatilized during carbonization to form a hollow core, and said sulfonated outer layer is carbonized to form a carbon outer layer, wherein at least the sulfonated outer layer is comprised of a polyolefin.
A method for producing a hollow carbon fiber, the method comprising subjecting a multi-component polymer fiber composite comprised of a non-fugitive polymer outer layer and a fugitive core to a fugitive removal step to produce a hollow polymer fiber, and subjecting said hollow polymer fiber to a sulfonation step followed by a carbonization step to convert said hollow polymer fiber to said hollow carbon fiber, wherein at least the non-fugitive polymer outer layer is comprised of a polyolefin.
A method for producing a carbon fiber possessing a circular- or complex-shaped outer surface, the method comprising subjecting a multi-component polymer fiber composite to a carbonization step, wherein said multi-component polymer fiber composite is comprised of a sulfonated core having a circular or complex shape and an unsulfonated outer layer, wherein said unsulfonated outer layer is volatilized during carbonization, and said sulfonated core is carbonized to form a carbon fiber having a circular- or complex-shaped outer surface, wherein at least the sulfonated core is comprised of a polyolefin.
A method for producing a carbon fiber possessing a circular- or complex-shaped outer surface, the method comprising subjecting a multi-component polymer fiber composite comprised of a non-fugitive polymer core having a circular or complex shape and a fugitive outer layer to a fugitive removal step to produce a polymer fiber having a circular- or complex-shaped outer surface, and subjecting said polymer fiber having a circular- or complex-shaped outer surface to a sulfonation step followed by a carbonization step to convert said polymer fiber possessing a circular- or complex-shaped outer surface to a carbon fiber possessing a circular- or complex-shaped outer surface, wherein at least the non-fugitive polymer core is comprised of a polyolefin.
Dependencies are inferred from the claim text.