Disclosed are methods for preparing a lignin/poly(vinyl alcohol) (PVA) fiber and for preparing a lignin/polyacrylonitrile (PAN) fiber. The methods can comprise adding a dope of lignin and PVA or a dope of lignin and PAN to a coagulation bath containing a solvent comprising one or more components, wherein the one or more components are present in the solvent in concentrations based on the hydrogen bonding character (f.sub.H) of the solvent, the polar character (f.sub.P) of the solvent, and the dispersive character (f.sub.D) of the solvent; and gel-spinning a lignin/PVA fiber or a lignin/PAN fiber from the coagulation bath.

The present invention relates to a method for manufacturing thermally stabilized, non-sticky and stretchable fibers, which may be further processed into intermediate carbon fibers and finally also carbon fibers. Uses of said fibers are also disclosed. Also a highly oriented intermediate carbon fiber is disclosed together with a highly oriented carbon fiber.

The present invention relates to a method for manufacturing thermally stabilized, non-sticky and stretchable fibers, which may be further processed into intermediate carbon fibers and finally also carbon fibers. Uses of said fibers are also disclosed. Also a highly oriented intermediate carbon fiber is disclosed together with a highly oriented carbon fiber.

The present invention relates to a method of producing lignin with reduced amount of odorous substances comprising the steps of: i) providing a solid phase lignin containing starting material to be contacted with a water solution comprising alcohol; ii) dissolving at least guaiacol and etylguaiacol content from the lignin into the water solution, and iii) draining off the water solution with its content of guaiacol and etylguaiacol; iv) obtaining a lignin material with a reduced content guaiacol and etylguaiacol. The alcohol is preferably a C1-C4 alcohol, preferably ethanol. The invention also relates to a lignin product with reduced odour obtained and/or obtainable by the method and to the use of the obtained lignin as a component in polymer blends, an additive or filler in building materials, as binding agent in adhesives, and/or for the production of a carbon fibre, especially in indoor applications.

The present invention relates to a method of producing lignin with reduced amount of odorous substances comprising the steps of: i) providing a solid phase lignin containing starting material to be contacted with a water solution comprising alcohol; ii) dissolving at least guaiacol and etylguaiacol content from the lignin into the water solution, and iii) draining off the water solution with its content of guaiacol and etylguaiacol; iv) obtaining a lignin material with a reduced content guaiacol and etylguaiacol. The alcohol is preferably a C1-C4 alcohol, preferably ethanol. The invention also relates to a lignin product with reduced odour obtained and/or obtainable by the method and to the use of the obtained lignin as a component in polymer blends, an additive or filler in building materials, as binding agent in adhesives, and/or for the production of a carbon fibre, especially in indoor applications.

The present disclosure provides derivatives of native lignin suitable for production of carbon fibres wherein the derivatives of native lignin have a certain alkoxy content and/or a certain carbon content. The present lignin derivatives can have acceptable spinnability performance characteristics for producing carbon fibres having acceptable tensile strengths and acceptable modulus of elasticity.

The present disclosure provides derivatives of native lignin suitable for production of carbon fibres wherein the derivatives of native lignin have a certain alkoxy content and/or a certain carbon content. The present lignin derivatives can have acceptable spinnability performance characteristics for producing carbon fibres having acceptable tensile strengths and acceptable modulus of elasticity.

A formulation for melt-preparation of lignin-based fibres, which are precursors of carbon fibres. The formulation includes lignin, a plasticiser and a cross-linking agent capable of cross-linking with the lignin at a temperature at least 10 C. higher than the glass-transition temperature of the intimate blend of the lignin and the plasticizer. A method for preparing lignin-based fibres using this formulation includes the hot extrusion spinning of an intimate blend of the components of the formulation, under adequate conditions for cross-linking the cross-linking agent and the lignin in the terminal area of the extrusion device used.

A formulation for melt-preparation of lignin-based fibres, which are precursors of carbon fibres. The formulation includes lignin, a plasticiser and a cross-linking agent capable of cross-linking with the lignin at a temperature at least 10 C. higher than the glass-transition temperature of the intimate blend of the lignin and the plasticizer. A method for preparing lignin-based fibres using this formulation includes the hot extrusion spinning of an intimate blend of the components of the formulation, under adequate conditions for cross-linking the cross-linking agent and the lignin in the terminal area of the extrusion device used.

A method of producing carbon fibers by forming, via a one pot acidic precipitation, a precipitated lignin from a precipitation solution by contacting a lignin solution and an acid solution, wherein the precipitation solution comprises the lignin solution and the acid solution, wherein the lignin solution comprises lignin dissolved in a basic aqueous solution, and wherein the acidic solution has a pH of less than or equal to about 6, 5, 4, 3, or 2; forming precursor fibers from the precipitated lignin; and subjecting the precursor fibers to thermostabilization, carbonization, or both to produce the carbon fibers.