Thermal stabilization of poly(hexamethylene adipamide) fibers in the presence of ferric chloride prior to carbonization

Karacan, İsmail; Tunçel, Kemal Şahin

doi:10.1016/j.polymdegradstab.2013.05.001

Cited by 16 publications

(11 citation statements)

References 49 publications

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“…A similar trend was reported in some other studies. [ 71,72,81 ] In particular, even with 5 min of stabilization, the intensity of the (100) crystal planes decreased by about 72%. After 60 min of stabilization, the intensity of the crystal plane (110) completely disappeared, and the peak height was not seen.…”

Section: Resultsmentioning

confidence: 98%

“…As in similar studies, it was observed that the volume density increased as the thermal stabilization time increased. [ 71,72 ] The volume density values increased between approximately 5% and 21% with increased stabilization time compared to the untreated sample. The increase in density values after thermal stabilization is interpreted as packing the macromolecule chains closer to each other due to the cyclization of the nitrile groups in the PAN structure.…”

Section: Resultsmentioning

confidence: 99%

“…A similar trend was reported in some other studies. [71,72,81] In particular, even with 5 min of stabilization, the intensity of the (100) crystal planes decreased by F I G U R E 1 2 (A) The change of the intensity of (100) and (110) band, (B) the change of crystallinity (%), and (C) X-ray stabilization index values of the original and stabilized polyacrylonitrile (PAN) samples about 72%. After 60 min of stabilization, the intensity of the crystal plane (110) completely disappeared, and the peak height was not seen.…”

Section: X-ray Diffractionmentioning

confidence: 99%

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The impact of guanidine carbonate incorporation on the molecular structure of polyacrylonitrile precursor fiber stabilized by a multistep heat treatment strategy

Tunçel

Rahman

Demirel

et al. 2022

Polymer Engineering & Sci

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Thermal‐oxidative stabilization of the polyacrylonitrile (PAN) precursor was performed employing a multi‐step heat treatment strategy in an air circulating furnace. In this approach, the applied temperature was gradually increased from 200°C to 250°C employing several stages for different stabilization durations. Fifteen percent guanidine carbonate (GC) was found as optimum to incorporate with the PAN precursor fibers to accelerate the thermal‐oxidative stabilization process. Characterization techniques, including X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensile strength, volume density, linear density, fiber thickness, and burning test have been performed to monitor the changes in PAN structure. Test results of the stabilized samples were compared with the reference sample results to demonstrate the accelerating effect of GC integration. Findings showed that GC pretreatment enhanced and accelerated the cyclization of nitrile groups in the PAN polymer structure and allowed the quicker formation of a thermally stable structure. The analysis of the experimental results revealed that GC integration and employing the multi‐step heat treatment strategy helps greatly to cut the overall PAN‐based carbon fiber production cost.

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: X-ray Diffractionmentioning

confidence: 99%

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The impact of guanidine carbonate incorporation on the molecular structure of polyacrylonitrile precursor fiber stabilized by a multistep heat treatment strategy

Tunçel

Rahman

Demirel

et al. 2022

Polymer Engineering & Sci

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“…The crystallinity decreased from 34.58% for PA66 to 26.14% for FRPA66‐5. X c was calculated by Equation , where ΔH m is the melting enthalpy of FRPA66 samples measured by DSC and

Δ H_{m}^{*}

is the melting enthalpy of the 100% crystalline PA66 . The value of

Δ H_{m}^{*}

is 190.0 J·g −1 for PA66 …”

Section: Resultsmentioning

confidence: 99%

Preparation and characterizations of inherent flame retarded polyamide 66 containing the phosphorus linking pendent group

Liu

Zhang

et al. 2017

Polymers for Advanced Techs

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Polyamide 66 (PA66) containing the phosphorus linking pendent group with inherent flame retardancy property was prepared by condensation polymerization of hexamethylene diammonium adipate (AH salt) and 9,10-dihydro-10-[2,3-di(hydroxycarbonyl)propyl]-10phosphaphenanthrene-10-oxide (DDP) as a co-monomer. Prior to condensation polymerization, DDP was reacted with hexamethylene diamine (HMDA), which made DDP easier to react with AH salt. Then, the DDP-HMDA was introduced into AH salt solution to prepare inherent flame retarded PA66 (FRPA66). Fourier transform infrared spectra, nuclear magnetic resonance spectra, gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, tensile test, vertical burning test, limiting oxygen index test, cone calorimetry, and scanning electron microscopy were utilized to investigate the properties of FRPA66.Experimental results indicated that the bulky pendent phosphorus group tended to destroy the structure regularity of FRPA66 and the molecular weight, crystallinity, and thermal stability reduced. The tensile strength of FRPA66 containing 5 wt% of DDP was 58.44 MPa, and it can achieve a V-0 rating according to the vertical burning test with the limiting oxygen index value of 33.2%. This indicated that the inherent flame retarded PA66 expanded the application of PA66 materials.

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“…Numerous research methods used to improve the mechanical properties through the structural development of the crystal orientations of nylon 6,6 fibres have been reported, these include spinning (the high-speed melt spinning [ 20 , 21 , 22 , 23 ], the wet spinning [ 24 ], the dry-jet wet spinning of the reversible solvent-counter-ions (GaCl 3 ) complexation [ 25 , 26 , 27 , 28 , 29 , 30 , 31 ] and the solution spinning of the reversible superheated water-counter-ions (LiI) shielding [ 32 ]) and the drawing (the heat drawing and the annealing [ 33 , 34 , 35 , 36 , 37 ]) methods. It is worth to note here that the montmorillonite clay (MMT) [ 38 , 39 , 40 ], the multi-wall carbon nanotube (MWNT) [ 41 , 42 ] and the nanodiamond [ 43 ] nanocomposite methods as well as the lithium chloride (LiCl) [ 44 ] and the ferric chloride (FeCl 3 ) [ 45 ] interactions have, also, been used to modulate the crystal structure of nylon 6,6 materials.…”

Section: Introductionmentioning

confidence: 99%

Transient Confinement of the Quaternary Tetramethylammonium Tetrafluoroborate Salt in Nylon 6,6 Fibres: Structural Developments for High Performance Properties

Dawelbeit

2021

Materials

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A temporary confinement of the quaternary tetramethylammonium tetrafluoroborate (TMA BF4) salt among polyamide molecules has been used for the preparation of aliphatic polyamide nylon 6,6 fibres with high-modulus and high-strength properties. In this method, the suppression or the weakening of the hydrogen bonds between the nylon 6,6 segments has been applied during the conventional low-speed melt spinning process. Thereafter, after the complete hot-drawing stage, the quaternary ammonium salt is fully extracted from the drawn 3 wt.% salt-confined fibres and the nascent fibres are, subsequently, thermally stabilized. The structural developments that are acquired in the confined-nylon 6,6 fibres are ascribed to the developments of the overall fibres’ properties due to the confinement process. Surprisingly, unlike the neat nylon 6,6 fibres, the X-ray diffraction (XRD) patterns of the as-spun salt-confined fibres have shown diminishing of the (110)/(010) diffraction plane that obtained pseudohexagonal-like β’ structural phase. Moreover, the β’ pseudohexagonal-like to α triclinic phase transitions took-place due to the hot-drawing stage (draw-induced phase transitions). Interestingly, the hot-drawing of the as-spun salt-confined nylon 6,6 fibres achieved the same maximum draw ratio of 5.5 at all of the drawing temperatures of 120, 140 and 160 °C. The developments that happened produced the improved values of 43.32 cN/dtex for the tensile-modulus and 6.99 cN/dtex for the tensile-strength of the reverted fibres. The influences of the TMA BF4 salt on the structural developments of the crystal orientations, on the morphological structures and on the improvements of the tensile properties of the nylon 6,6 fibres have been intensively studied.

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Thermal stabilization of poly(hexamethylene adipamide) fibers in the presence of ferric chloride prior to carbonization

Cited by 16 publications

References 49 publications

The impact of guanidine carbonate incorporation on the molecular structure of polyacrylonitrile precursor fiber stabilized by a multistep heat treatment strategy

The impact of guanidine carbonate incorporation on the molecular structure of polyacrylonitrile precursor fiber stabilized by a multistep heat treatment strategy

Preparation and characterizations of inherent flame retarded polyamide 66 containing the phosphorus linking pendent group

Transient Confinement of the Quaternary Tetramethylammonium Tetrafluoroborate Salt in Nylon 6,6 Fibres: Structural Developments for High Performance Properties

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