On the exotherm of polyacrylonitrile: Pyrolysis of the homopolymer under inert conditions

Peebles, L. H.; Peyser, Paul; Snow, Arthur W.; Peters, Wanda

doi:10.1016/0008-6223(90)90073-8

Cited by 39 publications

(10 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Cyclization is the most important reaction in stabilization process. The cyclization of the nitrile groups is an exothermic reaction and that the evolution of gaseous products accompanies this reaction [46]. The reaction is necessary to hold molecules in fiber together and increases the stiffness [47e50].…”

Section: Cyclization Reactionmentioning

confidence: 99%

A review of heat treatment on polyacrylonitrile fiber

Rahaman

Ismail

Mustafa

2007

Polymer Degradation and Stability

1,245

856

View full text Add to dashboard Cite

Section: Cyclization Reactionmentioning

confidence: 99%

A review of heat treatment on polyacrylonitrile fiber

Rahaman

Ismail

Mustafa

2007

Polymer Degradation and Stability

1,245

856

View full text Add to dashboard Cite

“…Cyclization is the most important reaction in stabilization process, resulting in formation of ladder structure that is vital for fibers to last during high temperature carbonization process [15]. The process is an exothermic process with evolution of gaseous products and aids in holding the molecule together and make the structure stiffer [13,16]. IR results after high temperature carbonization process, figure (i), show absence of all above indicated peaks corresponding to -C=N and C-H, pointing out that carbonization has taken place.…”

Section: Characterization and Analysismentioning

confidence: 99%

Development and Structural Integration of Electrospun Carbon Nanofibers with Multi-layer Graphene Patches

A.B¹,

Dreyer²,

Aprojanz³

et al. 2018

Nano Tech Appl

View full text Add to dashboard Cite

Among the carbon based nanostructured materials, Carbon Nanofibers (CNF) have got unique prominence since past decade due to excellent mechanical and electrical properties combined by their cheap and easy fabrication process. CNF with graphene layered structure were developed by electrospinning of PAN (Polyacrylonitrile) and subsequent post treatments under specialized conditions. The assembly of graphene layers in the form of patches on the CNF surface was examined by Raman spectroscopy and TEM. Structural changes of CNF under different temperatures from 800°C-1500°C in reducing atmosphere have been investigated. Crystallite size, ID/IG, and FWHM for D and G characteristic bands were evaluated via Raman peak fitting and X-ray diffraction spectroscopy. Results have shown that CNF carbonized at 1500°C with prior external straining (creep stress) applied during the oxidative stabilization process showed emergence of a symmetrical sharp 2D peak in Raman spectrum with I2D/IG ratio of nearly multi-layer graphene. High temperature heat treatment along with creep stress during the stabilization process results in transforming more of the amorphous carbon into the ordered graphitic domains, leading to assembly of graphene layers on carbon nanofiber surface.

show abstract

“…Cyclization is an exothermic reaction. If it occurs too quickly, the fiber may be damaged due to excessive shrinkage, significant mass loss and even melting and fusing of the fiber [13]. If cyclization occurs too slowly, the fibers may be partially stabilized, the unstabilized portion will vaporize during carbonization [3], and productivity and power consumption will suffer.…”

Section: Introductionmentioning

confidence: 99%

Predicting the Cyclization Index and Density of Stabilized Polyacrylonitrile Tow from Processing Conditions

et al. 2021

View full text Add to dashboard Cite

The production of polyacrylonitrile (PAN)-based carbon fiber includes two major steps, stabilization (oxidization) and carbonization. Stabilization is a slow and energy-consuming process and involves using a series of ovens that need to be carefully tuned to achieve desirable quality at the lowest cost. This usually involves meeting fiber density or cyclization levels at each zone of the oxidation furnace, often achieved through trial and error by a team of skilled operators. In this work, a simple empirical model was developed to predict density from oven system parameters and cyclization onset temperature of the PAN feedstock, parametrized as Sn, representing the oxidation depth. The relative cyclization index (RCI) and density of the fibers were analyzed after various oxidation treatments and were used to derive the model parameters. The RCI of stabilized fiber was well represented by a logistic function incorporating Sn while the fiber density was well predicted by a polynomial function of RCI. The model was verified using stabilization trials conducted on the same precursor in a continuous oven system and in a batch oven, and then on a second commercial precursor using the batch oven. Statistical analysis on these trials shows good agreement with model predictions.

show abstract

On the exotherm of polyacrylonitrile: Pyrolysis of the homopolymer under inert conditions

Cited by 39 publications

References 27 publications

A review of heat treatment on polyacrylonitrile fiber

A review of heat treatment on polyacrylonitrile fiber

Development and Structural Integration of Electrospun Carbon Nanofibers with Multi-layer Graphene Patches

Predicting the Cyclization Index and Density of Stabilized Polyacrylonitrile Tow from Processing Conditions

Contact Info

Product

Resources

About