Polymer-derived ceramic fibers and methods of preparing the same
AssigneeKansas State University Research Foundation
InventorsGurpreet Singh, Zhongkan Ren
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Abstract
Ceramic matrix composite (CMC) materials are a desired solution for lightweight and high temperature applications. CMC materials can be reinforced with polymer-derived ceramic (PDC) fibers, which advantageously possess intrinsic thermal stability and high mechanical strength. Carbon-rich SiOC and SiOCN fibers were synthesized via hand-drawing and electrospinning polymer pyrolysis of a hybrid precursor materials with the aid of a spinning reagent. The prepared fibers are crosslinked and pyrolyzed for polymer-to-ceramic conversion.
Claims13
A method of producing ceramic fiber materials comprising:
- forming a reaction mixture comprising a liquid preceramic composition and a spinning reagent, the liquid preceramic composition consisting essentially of a crosslinking agent and a siloxane and/or a silazane, the reaction mixture comprising a gel;
- spinning preceramic polymer fibers from the gel;
- crosslinking the preceramic polymer fibers to form crosslinked preceramic polymer fibers;
- pyrolyzing the crosslinked preceramic polymer fibers to form the ceramic fiber materials, wherein the ceramic fiber material comprises free carbon, the pyrolyzing step comprising heating the crosslinked preceramic polymer fibers to a pyrolysis temperature of about 600° C. to about 1000° C. at a rate of about 1° C./minute to about 3° C./minute;
- and
- annealing the ceramic fiber material at the pyrolysis temperature for about 5 minutes to about 30 minutes.
A method of producing silicon oxycarbide fibers comprising:
- forming a reaction mixture comprising a liquid preceramic composition and a spinning reagent, the liquid preceramic composition consisting essentially of a crosslinking agent and a siloxane and/or a silazane, the spinning reagent comprising polyacrylic acid, polyvinylpyrrolidone, and/or polyacrylonitrile, the reaction mixture comprising a gel;
- spinning preceramic polymer fibers from the gel using a wet spinning, a gel spinning, or an electrospinning process;
- heating the preceramic polymer fibers to form crosslinked preceramic polymer fibers;
- pyrolyzing the crosslinked preceramic polymer fibers to form the silicon oxycarbide fibers, wherein the silicon oxycarbide fibers comprise free carbon, the pyrolyzing step comprising heating the preceramic polymer fibers to a pyrolysis temperature of about 600° to about 1000° C. at a rate of about 1° C./minute to about 3° C./minute;
- and
- annealing the silicon oxycarbide fibers at the pyrolysis temperature for about 5 minutes to about 30 minutes.
Dependencies are inferred from the claim text.