Preparation of C/C‐SiC Composites from All‐Cellulose Precursors

Schneck, Tanja; Müller, Alexandra; Hermanutz, Frank; Buchmeiser, Michael R.

doi:10.1002/mame.201800763

Cited by 4 publications

(4 citation statements)

References 30 publications

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“…Such new developments were highlighted in a review by Hermanutz et al [ 146 ] Interesting technical applications such as all‐cellulose composites, spinning of polymer blends (e.g., cellulose plus chitin) and precursors for carbon fibers were described. [ 147 ] For carbon fiber precursors, it was shown that the use of different ILs makes it possible to co‐spin lignin (another abundant renewable wood‐based macromolecule) with cellulose. This can result in an increased yield of the final carbon fiber as well as reduced processing time during the stabilization step of the conversion to carbon fibers.…”

Section: Regeneration Of Cellulose In Different Physical Formsmentioning

confidence: 99%

Cellulose Regeneration and Chemical Recycling: Closing the “Cellulose Gap” Using Environmentally Benign Solvents

Seoud

Kostag

Jedvert

et al. 2020

Macro Materials & Eng

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matched by synthetic fibers. Therefore, the demand on natural and fabricated cellulosic fibers is expected to continue and rise. The production of cotton, however, is not expected to meet this demand because of restrictions on farmland use and availability of irrigation water. [3] Anticipating the so-called "the cellulosic fiber gap," [1] the textile industry currently leads several initiatives for developing fibers that can complement cotton. [3] Consequently, there is incitement and opportunities for an increase in use of cellulose from other sources, in particular wood, and increased interest in physical (i.e., mechanical) and chemical recycling (CR) of biopolymers. [4] Production of fibers and other artifacts from cellulose extracted from wood involves chemical or physical dissolution of the biopolymer, followed by its regeneration in the desired physical form in an appropriate bath. The most important example of cellulose chemical dissolution (i.e., via covalent bond formation) is the viscose rayon fiber, produced by regeneration of cellulose from its xanthate in acid bath. The Lyocell fiber process involves, however, physical dissolution of cellulose in N-methylmorpholine-N-oxide (NMMO) hydrate, followed by regeneration in an aqueous bath. [5] Cellulose regeneration is not restricted to formation of fibers. The biopolymer and its derivatives, in particular esters, can be "shaped" into other physical forms including spheres of different diameters (down to the nanoscale), films produced by casting and spin coating, and nonwoven mats produced by electrospinning or solution blowing. This review covers some recent advances of the regeneration of cellulose from alkali solutions and ionic solvents, in particular those based on imidazole, quaternary ammonium electrolytes (QAEs), and salts of heterocyclic super-bases. We refer to these ionic solvents collectively as ionic liquids (ILs). Representative examples of the ILs employed for cellulose dissolution are shown in Figure 1. These solvents dissolve cellulose samples of a wide range of degrees of polymerization (DPs) and indices of crystallinity (Ics). For practical reasons, binary mixtures of ILs with molecular solvents (MSs) are used alongside pure ILs. This use is advantageous because of the concomitant decrease in solution viscosity; there are many examples where the binary solvent mixture dissolves more cellulose than the parent pure IL. [5] Strategies to mitigate the expected "cellulose gap" include increased use of wood cellulose, fabric reuse, and recycling. Ionic liquids (ILs) are employed for cellulose physical dissolution and shaping in different forms. This review focuses on the regeneration of dissolved cellulose as nanoparticles, membranes, nonwoven materials, and fibers. The solvents employed in these applications include ILs and alkali solutions without and with additives. Cellulose fibers obtained via the carbonate and carbamate processes are included. Chemical recycling (CR) of polycotton (cellulose plus poly(ethylene terephthalate)) is addressed...

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Section: Regeneration Of Cellulose In Different Physical Formsmentioning

confidence: 99%

Cellulose Regeneration and Chemical Recycling: Closing the “Cellulose Gap” Using Environmentally Benign Solvents

Seoud

Kostag

Jedvert

et al. 2020

Macro Materials & Eng

View full text Add to dashboard Cite

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“…While most publications describe the production of staple fibers suitable for use in the textile industry, the use of cellulosic fibers is by far not limited to these applications, the mores since special viscose fibers are used as tire cord fibers and as reinforcement fibers for composites (Schneck et al 2019;Spörl et al 2017a;Wooding 1995;Zadorecki et al 1986). In this study we present an IL-based spinning process that allows for the production of endless multi-filament fibers with properties comparable to those of commercial tire cord fibers.…”

Section: Introductionmentioning

confidence: 99%

High-performance cellulosic filament fibers prepared via dry-jet wet spinning from ionic liquids

et al. 2021

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We report on a new process for the spinning of high-performance cellulosic fibers. For the first time, cellulose has been dissolved in the ionic liquid (IL) 1-ethyl-3-methylimidazolium octanoate ([C2C1im][Oc]) via a thin film evaporator in a continuous process. Compared to other ILs, [C2C1im][Oc] shows no signs of hydrolysis with water. For dope preparation the degree of polymerization of the pulp was adjusted by electron beam irradiation and determined by viscosimetry. In addition, the quality of the pulp was evaluated by means of alkali resistance. Endless filament fibers have been spun using dry-jet wet spinning and an extruder instead of a spinning pump, which significantly increases productivity. By this approach, more than 1000 m of continuous multifilament fibers have been spun. The novel approach allows for preparing cellulose fibers with high Young's modulus (33 GPa) and unprecedented high tensile strengths up to 45 cN/tex. The high performance of the obtained fibers provides a promising outlook for their application as replacement material for rayon-based tire cord fibers.

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“…[ 11–14 ] Consequently, alternative precursor materials and processes are highly needed. Current research focuses on alternative precursors from low‐cost, renewable resources such as cellulose [ 15–20 ] or lignin. [ 21–32 ] Alternatively, melt spinnable PAN copolymers have again moved into the center of interest.…”

Section: Introductionmentioning

confidence: 99%

“…Compared to a PAN‐based CF process, almost 60% of the costs can be saved in precursor synthesis. [ 5 ] Another outstanding property of PE is its very high theoretical carbon yield of 85 wt%, which exceeds the one of other CF precursors such as cellulose (44 wt%) [ 15–20 ] or lignin (< 65 wt%). [ 21–32,38 ] And indeed, carbon yields from PE precursors of up to 76 wt% have been reported.…”

Section: Introductionmentioning

confidence: 99%

Structure Evolution in Polyethylene‐Derived Carbon Fiber Using a Combined Electron Beam‐Stabilization‐Sulphurization Approach

Frank

Muks

Ota

et al. 2021

Macro Materials & Eng

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A new approach is described for the production of poly(ethylene) (PE) derived carbon fibers (CFs) that entails the melt spinning of PE fibers from a suitable precursor, their cross‐linking by electron beam (EB) treatment, and sulphurization with elemental sulphur (S8), followed by pyrolysis and carbonization. Instead of focusing on mechanical properties, analysis of CF structure formation during all process steps is carried out by different techniques comprising solid‐state nuclear magnetic resonance spectroscopy, thermogravimetric analysis coupled to mass spectrometry/infrared spectroscopy, elemental analysis, energy dispersive X‐ray scattering, scanning electron microscopy, Raman spectroscopy, and wide‐angle X‐ray diffraction. A key step in structure formation is the conversion of PE into poly(thienothiophene)s during sulphurization; these species are stabile under inert gas up to 700 °C as confirmed by Raman analysis. Above this temperature, they condense into poly(napthathienophene)s, which are then converted into graphite‐type structures during pyrolysis.

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Preparation of C/C‐SiC Composites from All‐Cellulose Precursors

Cited by 4 publications

References 30 publications

Cellulose Regeneration and Chemical Recycling: Closing the “Cellulose Gap” Using Environmentally Benign Solvents

Cellulose Regeneration and Chemical Recycling: Closing the “Cellulose Gap” Using Environmentally Benign Solvents

High-performance cellulosic filament fibers prepared via dry-jet wet spinning from ionic liquids

Structure Evolution in Polyethylene‐Derived Carbon Fiber Using a Combined Electron Beam‐Stabilization‐Sulphurization Approach

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