Thermal properties and flame retardancy of an intumescent flame-retarded epoxy system containing phosphaphenanthrene, triazine-trione and piperidine

  • 50 Accesses

  • 2 Citations


A phosphaphenanthrene/piperidine-containing phenolic derivative (PHTD) was synthesized through the one-pot reaction between triacetonediamine, p-hydroxybenzaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. The intumescent reactive flame-retardant epoxy thermosets (P-0.25, P-0.5, P-0.75 and P-1.0) were composed of diglycidyl ether of bisphenol-A, 1,3,5-triglycidyl isocyanurate (TGIC), 4,4′-diamino-diphenyl sulfone (DDS) and PHTD. Due to the incorporation of PHTD and TGIC, the flame retardancy of EP samples was remarkably improved. For instance, the LOI value and UL94 rating for P-0.75 sample with only 0.75 mass% phosphorus reached 36.6% and V-0. The average of heat release rate, peak of heat release rate and total heat release for P-1.0 system were decreased by 35.6%, 52.5% and 36.4% compared with those for EP/DDS system. During combustion, plenty of PO radicals, hindered amine and isocyanate fragments were generated by the pyrolysis of PHTD and TGIC in gaseous phase, which suppressed the combustion reaction and diluted the fuels. In condensed phase, the pyrolytic products of phosphaphenanthrene and triazine-trione groups jointly promoted the formation of a compact and intumescent char layer to isolate heat and oxygen. The remarkable improvement of flame retardancy of EP thermoset was ascribed to the flame-retardant effects of PHTD and TGIC in gaseous and condensed phases.

This is a preview of subscription content, log in to check access.

Access options

Buy single article

Instant unlimited access to the full article PDF.

US$ 39.95

Price includes VAT for USA

Scheme 1
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14


  1. 1.

    Liu Z, Dai M, Zhang Y, Gao X, Zhang Q. Preparation and performances of novel waterborne intumescent fire retardant coatings. Prog Org Coat. 2016;95:100–6.

  2. 2.

    He X, Zhang W, Yang R. The characterization of DOPO/MMT nanocompound and its effect on flame retardancy of epoxy resin. Compos Part A Appl Sci Manuf. 2017;98:124–35.

  3. 3.

    Unlu S, Dogan S, Dogan M. Comparative study of boron compounds and aluminum trihydroxide as flame retardant additives in epoxy resin. Polym Adv Technol. 2014;25:769–76.

  4. 4.

    Liu Y, Babu H, Zhao J, Goñi-Urtiaga A, Sainz R, Ferritto R, Pita M, Wang D. Effect of Cu-doped graphene on the flammability and thermal properties of epoxy composites. Compos Part B Eng. 2016;89:108–16.

  5. 5.

    Chen T, Chen X, Wang M, Hou P, Jie C, Li J, Xu Y, Zeng B, Dai L. A novel halogen-free co-curing agent with linear multi-aromatic rigid structure as flame-retardant modifier in epoxy resin. Polym Adv Technol. 2018;29:603–11.

  6. 6.

    Schartel B, Balabanovich A, Braun U, Knoll U, Artner J, Ciesielski M, Döring M, Perez R, Sandler J, Altstädt V, Hoffmann T, Pospiech D. Pyrolysis of epoxy resins and fire behavior of epoxy resin composites flame-retarded with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide additives. J Appl Polym Sci. 2007;104:2260–9.

  7. 7.

    Yang J, Wang Z, Liu L. Synthesis of a novel phosphorus-containing dicyclopentadiene novolac hardener and its cured epoxy resin with improved thermal stability and flame retardancy. J Appl Polym Sci. 2017;134:44599.

  8. 8.

    Artner J, Ciesielski M, Walter O, Döring M, Perez R, Sandler J, Altstädt V, Schartel B. A novel DOPO-based diamine as hardener and flame retardant for epoxy resin systems. Macromol Mater Eng. 2008;293:503–14.

  9. 9.

    Zhou L, Zhang G, Li J, Jing Z, Qin J, Feng Y. The flame retardancy and thermal stability properties of flame-retarded epoxy resins based on α-hydroxyphosphonate cyclotriphosphazene. J Therm Anal Calorim. 2017;129:1667–78.

  10. 10.

    Huo S, Wang J, Yang S, Chen X, Zhang B, Wu Q, Zhang B. Flame-retardant performance and mechanism of epoxy thermosets modified with a novel reactive flame retardant containing phosphorus, nitrogen, and sulfur. Polym Adv Technol. 2018;29:497–506.

  11. 11.

    Zhang W, Li X, Yang R. Blowing-out effect in epoxy composites flame retarded by DOPO-POSS and its correlation with amide curing agents. Polym Degrad Stab. 2012;97:1314–24.

  12. 12.

    Wang X, Hu Y, Song L, Yang H, Xing W, Lu H. Synthesis and characterization of a DOPO-substitued organophosphorus oligomer and its application in flame retardant epoxy resins. Prog Org Coat. 2011;71:72–82.

  13. 13.

    Huo S, Wang J, Yang S, Wang J, Zhang B, Zhang B, Chen X, Tang Y. Synthesis of a novel phosphorus-nitrogen type flame retardant composed of maleimide, triazine-trione, and phosphaphenanthrene and its flame retardant effect on epoxy resin. Polym Degrad Stab. 2016;131:106–13.

  14. 14.

    Qian L, Ye L, Xu G, Liu J, Guo J. The non-halogen flame retardant epoxy resin based on a novel compound with phosphaphenanthrene and cyclotriphosphazene double functional groups. Polym Degrad Stab. 2011;96:1118–24.

  15. 15.

    Zhang Z, Yuan L, Guan Q, Liang G, Gu A. Synergistically building flame retarding thermosetting composites with high toughness and thermal stability through unique phosphorus and silicone hybridized graphene oxide. Compos Part A Appl Sci Manuf. 2017;98:174–83.

  16. 16.

    Brandsma S, Boer J, Leonards P, Cofino W, Covaci A, Leonards P. Organophosphorus flame-retardant and plasticizer analysis, including recommendations from the first worldwide interlaboratory study. TrAC Trends Anal Chem. 2013;43:217–28.

  17. 17.

    Qiu Y, Qian L, Xi W. Flame-retardant effect of a novel phosphaphenanthrene/triazine-trione bi-group compound on an epoxy thermoset and its pyrolysis behaviour. RSC Adv. 2016;61:56018–27.

  18. 18.

    Yang S, Zhang Q, Hu Y. Preparation and investigation of flame-retardant epoxy resin modified with a novel halogen-free flame retardant containing phosphaphenanthrene, triazine-trione, and organoboron units. J Appl Polym Sci. 2017;134:45291.

  19. 19.

    Xiong Y, Jiang Z, Xie Y, Zhang X, Xu W. Development of a DOPO-containing melamine epoxy hardeners and its thermal and flame-retardant properties of cured products. J Appl Polym Sci. 2013;127:4352–8.

  20. 20.

    Qian L, Qiu Y, Liu J, Xin F, Chen Y. The flame retardant group-synergistic-effect of a phosphaphenanthrene and triazine double-group compound in epoxy resin. J Appl Polym Sci. 2014;131:39709.

  21. 21.

    Huo S, Wang J, Yang S, Zhang B, Chen X, Wu Q, Yang L. Synthesis of a novel reactive flame retardant containing phosphaphenanthrene and piperidine groups and its application in epoxy resin. Polym Degrad Stab. 2017;146:250–9.

  22. 22.

    Xie H, Lai X, Li H, Zeng X. Synthesis of a novel macromolecular charring agent with free-radical quenching capability and its synergism in flame retardant polypropylene. Polym Degrad Stab. 2016;130:68–77.

  23. 23.

    Wang P, Yang F, Li L, Cai Z. Flame retardancy and mechanical properties of epoxy thermosets modified with a novel DOPO-based oligomer. Polym Degrad Stab. 2016;129:156–67.

  24. 24.

    Sun D, Yao Y. Synthesis of three novel phosphorus-containing flame retardants and their application in epoxy resins. Polym Degrad Stab. 2011;96:1720–4.

  25. 25.

    Jian R, Wang P, Xia L, Zheng X. Effect of a novel P/N/S-containing reactive flame retardant on curing behavior, thermal and flame-retardant properties of epoxy resin. J Anal Appl Pyrol. 2017;127:360–8.

  26. 26.

    Yan W, Yu J, Zhang M, Long L, Wang T, Qin S, Huang W. Novel flame retardancy effect of phenethyl-bridged DOPO derivative on epoxy resin. High Perform Polym. 2018;30:667–76.

  27. 27.

    Wirasaputra A, Yao X, Zhu Y, Liu S, Yuan Y, Zhao J, Fu Y. Flame-retarded epoxy resins with a curing agent of DOPO-triazine based anhydride. Macromol Mater Eng. 2016;301:982–91.

  28. 28.

    Liu Z, Dai M, Wang C, Zhang Q, Zhang Y, Jin B, Gao X. Effects of the addition mode and amount of organic montmorillonite in soft-core/hard-shell emulsion on fire protection, water resistance and stability of fire retardant coating. Prog Org Coat. 2016;101:350–8.

  29. 29.

    Tang S, Qian L, Liu X, Dong Y. Gas-phase flame-retardant effects of a bi-group compound based on phosphaphenanthrene and triazine-trione groups in epoxy resin. Polym Degrad Stab. 2016;133:350–7.

  30. 30.

    Yang S, Wang J, Huo S, Wang J, Tang Y. Synthesis of a phosphorus/nitrogen-containing compound based on maleimide and cyclotriphosphazene and its flame-retardant mechanism on epoxy resin. Polym Degrad Stab. 2016;126:9–16.

  31. 31.

    Huo S, Wang J, Yang S, Li C, Wang X, Cai H. Synthesis of a DOPO-containing imidazole curing agent and its application in reactive flame retarded epoxy resin. Polym Degrad Stab. 2019;159:79–89.

  32. 32.

    Liu Z, Dai M, Hu Q, Liu S, Gao X, Ren F, Zhang Q. Effect of microencapsulated ammonium polyphosphate on the durability and fire resistance of waterborne intumescent fire-retardant coatings. J Coat Technol Res. 2019;16:135–45.

Download references


The authors gratefully acknowledge the financial support for this work by the China Postdoctoral Science Foundation (No. 2018M642924), Hubei Province Postdoctoral Science and Technology Activity Project (No. G73), the National Defense Pre-Research Foundation of China (Grant No. JCKY2016110C008) and Science Foundation of Wuhan Institute of Technology.

Author information

Correspondence to Zhitian Liu or Jun Wang.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Huo, S., Liu, Z. & Wang, J. Thermal properties and flame retardancy of an intumescent flame-retarded epoxy system containing phosphaphenanthrene, triazine-trione and piperidine. J Therm Anal Calorim 139, 1099–1110 (2020) doi:10.1007/s10973-019-08467-3

Download citation


  • Epoxy resin
  • Intumescent reactive flame-retardant system
  • Phosphaphenanthrene
  • Piperidine
  • Triazine-trione