Melt spinning of propylene carbonate‐plasticized poly(acrylonitrile)‐<i>co</i>‐poly(methyl acrylate)

König, Simon; Kreis, Philipp; Reinders, Leonie; Beyer, Ronald; Wego, Andreas; Herbert, Christian; Steinmann, Mark; Frank, Erik; Buchmeiser, Michael R.

doi:10.1002/pat.4909

Cited by 8 publications

(4 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, the thermal single treatment sample, which was the precursor for processed #1 and #2, showed a higher softening point of 200 °C and did not cross-link between 200 and 270 °C, which is visible as a crossover of storage and loss modulus. Therefore, the processing temperature for melt spinning of the sample was chosen between 210 and 220 °C. − …”

Section: Results and Discussionmentioning

confidence: 99%

Chemistry and Properties of Carbon Fiber Feedstocks from Bitumen Asphaltenes

et al. 2023

Self Cite

View full text Add to dashboard Cite

Carbon fibers are materials of paramount importance for composites applied in fields such as aerospace engineering, medicine, and renewable energy. Currently, most of the production of carbon fibers uses polyacrylonitrile, which incurs significant greenhouse gas emissions and high production costs. Therefore, carbon fiber manufacturing from asphaltene-enriched feedstocks is attractive as it could add value to extra-heavy fossil fuels and cut down precursor costs by ∼90%. Recent studies indicate that some asphaltene-rich samples feature rheological properties that make them optimal for melt-spinning and carbon fiber production; in other cases, the spun asphaltene feedstocks are unsuitable for such applications. In this work, bitumen asphaltenes were subjected to upgrading processes under three distinctive conditions to tweak their rheological properties in order to produce carbon fibers. The treated samples were comprehensively studied by separations based on solubility and extrography, and subsequently characterized by ultrahigh-resolution mass spectrometry, gas-phase fragmentation, and thermogravimetric analysis. The results indicate that upon thermal processing, asphaltene-rich feedstocks produced a mixture with diverse solubility, i.e., maltenes, asphaltenes, and toluene-insoluble material. The molecular composition of remnant asphaltenes suggests that thermal treatment dramatically decreased molecular polydispersity in terms of the content of heteroatoms, alkyl chains, and structural motifs, i.e., single-core vs multicore, also known as island vs archipelago. The processed asphaltenes revealed high abundances of alkyl-depleted island species. Such thermally treated samples produced no stable carbon fibers. Conversely, a feedstock treated with molten sodium in a proprietary process designed to remove sulfur, revealed increased content of alkyl-side chains and archipelago structural motifs. This sample produced stable carbon fibers. Furthermore, thermal analysis coupled with mass spectrometry (TGA-HRMS) was conducted to understand thermal desorption and pyrolysis profiles for the samples, as well as the presence of occluded compounds and carbon residue formation. The TGA-HRMS results are consistent with extrography and IRMPD FT-ICR MS studies and confirmed the ultrahigh abundance of multicore compounds in the desulfurized sample. Although the sample size is limited, and thus, correlations between molecular composition and rheology properties are not achieved, this is the first study that aims to understand the role of feed composition in the ability to generate carbon fibers from asphaltene-enriched feedstocks. Collectively, the results indicate that samples comprised of abundant highly aromatic asphaltenes, dominant in alkyl-depleted single-core structures, are unlikely optimal for carbon fiber applications. Conversely, a sample with a marked increase in H/C, a significant decrease in S content, and abundant multicore species could generate stable carbon fibers. More studies are underway to find correlations ...

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Chemistry and Properties of Carbon Fiber Feedstocks from Bitumen Asphaltenes

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, propylene carbonate having a high boiling point remains in the fiber after cooling, and the fiber requires additional purification. Recently, propylene carbonate was used to plasticize AN and MA copolymers obtained by precipitation polymerization [ 127 ]. The authors varied several parameters at once: the composition of the copolymer (6.4–13.3 mol.% MA), M n from 19 to 47 kg⋅mol −1 , and dispersity Đ from 2.1 to 4.0.…”

Section: Physical Approach: Plasticizationmentioning

confidence: 99%

Melt-Spinnable Polyacrylonitrile—An Alternative Carbon Fiber Precursor

et al. 2022

View full text Add to dashboard Cite

The review summarizes recent advances in the production of carbon fiber precursors based on melt-spun acrylonitrile copolymers. Approaches to decrease the melting point of polyacrylonitrile and acrylonitrile copolymers are analyzed, including copolymerization with inert comonomers, plasticization by various solvents and additives, among them the eco-friendly ways to use the carbon dioxide and ionic liquids. The methods for preliminary modification of precursors that provides the thermal oxidative stabilization of the fibers without their melting and the reduction in the stabilization duration without the loss of the mechanical characteristics of the fibers are discussed. Special attention is paid to different ways of crosslinking by irradiation with different sources. Examples of the carbon fibers preparation from melt-processable acrylonitrile copolymers are considered in detail. A patent search was carried out and the information on the methods for producing carbon fibers from precursors based on melt-spun acrylonitrile copolymers are summarized.

show abstract

“…By contrast, when the solvent evaporates too slowly, the desired shape after melt-processing might not be stable or residual solvent could lead to foaming of the product during the subsequent thermal carbonization steps. [37][38][39] Alternatively, intrinsic plasticizers have been introduced by copolymerizing acrylonitrile with alkoxy-and alkyl acrylates or vinyl ethers as internal plasticizers, where the nitrile disturbing units can be split-off to raise T m and obtain an infusible material for the stabilization. However, the resulting changes in the molecular constitution of the polymer are either not well understood and irreproducible [31] or they require treatment that renders the resulting polymer unfit for stabilization-for example caustic treatment results in stoichiometric amounts of bound salt cations, which obviates controlled conversion into melt-processed carbon materials.…”

Section: Introductionmentioning

confidence: 99%

Switchable Polyacrylonitrile‐Copolymer for Melt‐Processing and Thermal Carbonization—3D Printing of Carbon Supercapacitor Electrodes with High Capacitance

2022

View full text Add to dashboard Cite

allowing fast charge-discharge kinetics, long cycling stability, and high capacitance. [1][2][3][4] Typically, such carbon electrodes are produced from active carbon powders. [5] The required structural integrity of the electrode can only be achieved by mixing the active carbon powder with binders; however, these binders are often electrochemically inert and decrease the overall performance of the electrodes by blocking the surface and porosity of the active material. To produce electrodes without binder, carbon fiber non-wovens present ideal materials for components in fuel cells, batteries, and supercapacitors. [5][6][7][8][9][10][11] The most widely used precursor for carbon fibers and materials is polyacrylonitrile (PAN). [12] PAN can be converted into carbon materials in a two-step thermal conversion process. The first step is called stabilization, in which the nitrile groups engage in mostly intramolecular cyclization reactions, forming polymer ribbons. Stabilization is conducted in an oxidative atmosphere between 200 and 300 °C. [13][14][15] Strong dipolar interactions between the nitrile groups entail a high melting temperature T m , well above the activation energy for the cyclization reaction-or stabilization. The second step is the carbonization, in which the polymer ribbons fuse to graphitic domains. Carbonization is conducted in an inert atmosphere above 1000 °C. [13,16,17] Because of its sensitivity towards high temperatures-with potential for thermal run-away, due to the exothermic nature of the stabilization reaction-PAN is typically processed from solution.However, solution processing limits the final architectures of the desired carbon materials to fibers and films. [18][19][20] Fiber spinning and film formation processes are energy consuming and costly, as they require large amounts of solvents, which on an industrial scale have to be recovered and eventually disposed of. [21][22][23][24] A much more economic manufacturing approach would be to process PAN from its melt. [17,25,26] This strategy would enable 3D printing techniques such as polymer extrusion-based additive manufacturing (EAM) with full freedom-ofdesign, expanding the possible shapes of carbon materials from 1D fibers and 2D films to monolithic 3D workpieces. To our advantage, EAM would allow fully automated shaping of PAN into complex structures. EAM is scalable, fast, solvent-free, and Polyacrylonitrile (PAN) represents the most widely used precursor for carbon fibers and carbon materials. Carbon materials stand out with their high mechanical performance, but they also show excellent electrical conductivity and high surface area. These properties render carbon materials suitable as electrode material for fuel cells, batteries, and supercapacitors. However, PAN has to be processed from solution before being thermally converted to carbon, limiting its final format to fibers, films, and non-wovens. Here, a PAN-copolymer with an intrinsic plasticizer is presented to reduce the melting temperature and avoid undesired entering of the t...

show abstract

Melt spinning of propylene carbonate‐plasticized poly(acrylonitrile)‐co‐poly(methyl acrylate)

Cited by 8 publications

References 34 publications

Chemistry and Properties of Carbon Fiber Feedstocks from Bitumen Asphaltenes

Chemistry and Properties of Carbon Fiber Feedstocks from Bitumen Asphaltenes

Melt-Spinnable Polyacrylonitrile—An Alternative Carbon Fiber Precursor

Switchable Polyacrylonitrile‐Copolymer for Melt‐Processing and Thermal Carbonization—3D Printing of Carbon Supercapacitor Electrodes with High Capacitance

Contact Info

Product

Resources

About