Mustafa Mukhtar

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Polymer Degradation and Stability


This paper describes the synthesis of a phosphorus-based flame retardant that is a chemical analog of diglycidyl ether of bisphenol A (DGEBA), as well as its incorporation as a matrix into carbon fiber laminates. Carbon fiber composites, if used for structural applications in mass transport vehicles (aircraft, trains), will require some aspects of improved fire performance to be used safely in those applications. The first phase of work involved the development of two separate synthesis routes to produce the flame retardant monomer, referred to as Phosphorus-DGEBA or simply P-DGEBA. The second step was to determine the viability of the compound's polymerization behavior through various experimental mixing formulations and curing conditions with an aliphatic amine curing agent. Differential scanning calorimetry (DSC) was used to evaluate the curing behavior of P-DGEBA when mixed with DGEBA and an aliphatic amine curing agent and dynamic mechanical analysis (DMA) was used to observe the glass transition temperature (Tg) of the carbon fiber composites. Thermogravimetric analysis (TGA) was also used to investigate the thermal stability and thermal degradation behaviors of the P-DGEBA/DGEBA blends. The final step included the fabrication of composites and their flammability testing using a cone calorimeter. DMA testing for P-DGEBA measured a Tg that was 10 °C higher than a DGEBA based carbon fiber composite, and DSC studies found that the P-DGEBA / DGEBA blend polymerized well with the amine curing agent. The TGA, MCC, and cone calorimeter data yielded mixed results with TGA and MCC suggesting a more condensed phase / char formation flame retardant activity for P-DGEBA, while cone calorimeter suggested a more vapor phase flame retardant activity. Overall, the P-DGEBA shows some promise as a reactive FR for epoxy + carbon fiber composites, but more study is needed.


Print: 0141-3910; Electronic: 1873-2321

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The document available for download following a required one-year embargo is the authors' accepted manuscript, provided in compliance with the publisher's policy on self-archiving. Permission documentation is on file.

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Researcher roles:

  • Mustafa Mukhtar: Investigation, Formal analysis, Data curation, Writing – original draft.
  • Donald Klosterman: Methodology, Formal analysis, Data curation, Writing – original draft.
  • Vladimir Benin: Methodology, Data curation, Formal analysis, Writing – original draft.
  • Alexander Morgan: Project administration, Methodology, Formal analysis, Data curation, Writing – original draft.





Peer Reviewed


P-DGEBA_manuscript_supplementary_VB.pdf (386 kB)
Supplemental data: NMR Spectra of Intermediate and Target Structures

TGA Supplementary data .pdf (908 kB)
Supplemental data: TGA results for neat P-DGEBA before and after drying process

Embargoed until Friday, September 22, 2023

Link to published version