Flame Retardant Compounds Used in Epoxy Resins

Year 2023, Volume: 28 Issue: 2, 775 - 802, 31.08.2023

Kaan Aksoy

https://doi.org/10.53433/yyufbed.1153811

Abstract

Epoxy resins are widely used in the electrical and electronic industries, shipping, coatings, adhesives and composites due to their excellent resistance to heat, moisture and chemicals, high tensile strength, low shrinkage during the curing process and excellent dimensional stability. Epoxy resins are highly flammable, and their flammability properties severely limit their use in areas requiring high flame resistance. Various solutions include halogen-based flame retardants, organic phosphorus compounds, mineral compounds, nitrogen, silicon additives, intumescent flame retardants, and nanoparticles have been proposed to overcome this challenging problem. Many phosphorous compounds are used in place of halogen compounds in flame retardant epoxy resins. Compared with flame retardant additives, reactive organic phosphorus compounds in epoxy resins show excellent flame retardant efficiency. In this paper, the classification of flame retardants (halogen, organic phosphorus compounds, minerals, nitrogen and silicon-based materials, intumescent flame retardant and nanocomposites), the combustion cycle of polymers and the application of flame retardants for epoxy resins, especially phosphorus-based materials, are investigated. Various flame retardant evaluation tests such as UL-94, limiting oxygen index and cone calorimetry are also briefly described.

Keywords

Coating, Epoxy, Flame retardant, Resins

Epoksi Reçinelerde Kullanılan Alev Geciktirici Bileşikler

Abstract

Epoksi reçineler, ısıya, neme ve kimyasallara karşı mükemmel dirençleri, yüksek gerilme mukavemeti, kürleme işlemi sırasında düşük büzülme ve mükemmel boyutsal stabiliteleri nedeniyle, elektrik ve elektronik endüstrileri, nakliye, kaplamalar, yapıştırıcılar ve kompozitlerde yaygın olarak kullanılmaktadır. Epoksi reçineler oldukça yanıcıdır ve yanıcılık özellikleri, yüksek alev dayanımı gerektiren alanlarda kullanımlarını ciddi şekilde sınırlar. Bu zorlu problemin üstesinden gelmek için halojen bazlı alev geciktiriciler, organik fosfor bileşikleri, mineral bileşikler, azot, silikon katkısı gibi çeşitli çözümler, şişen alev geciktirici ve nanopartiküller önerilmiştir. Çoğu fosforlu bileşik, alev geciktirici epoksi reçinelerinde halojen bileşikleri yerine kullanılır. Alev geciktirici katkılarla karşılaştırıldığında, epoksi reçinelerdeki reaktif organik fosfor bileşikleri mükemmel alev geciktirici verim gösterir. Bu bildiride, alev geciktiricilerin sınıflandırılması (halojen, organik fosfor bileşikleri, mineraller, nitrojen ve silikon esaslı malzemeler, şişen alev geciktirici ve nanokompozitler) polimerlerin yanma döngüsü ve epoksi reçineler için özellikle fosfor bazlı malzemeler olmak üzere alev geciktiricilerin uygulanması incelenmiştir. UL-94, sınırlayıcı oksijen indeksi ve koni kalorimetri gibi çeşitli alev geciktirici değerlendirme testleri de kısaca açıklanmıştır.

Keywords

Alev geciktirici, Epoksi, Kaplama, Reçine

References

• Akindoyo, J. O., Beg, M., Ghazali, S., Islam, M. R., Jeyaratnam, N., & Yuvaraj, A. R. (2016). Polyurethane types, synthesis and applications–a review. Research Advances, 6(115), 114453-114482. doi:10.1039/C6RA14525F
• Anioł, B., & Jankowski, D. (2018). Flame retardants of polymeric materials–calculation of the oxygen index. Thechnical Transaction, 9, 57-66. doi:10.4467/2353737XCT.18.131.8970
• ASTM. (1999). Standard test method for heat and visible smoke release rates for materials and products using an oxygen consumption calorimeter (E1354-99).
• ASTM. (2010) Standard test method for measuring the comparative burning characteristics of solid plastics in a vertical position (D3801).
• Babrauskas, V. (1984). Development of the cone calorimeter—a bench‐scale heat release rate apparatus based on oxygen consumption. Fire and Materials, 8(2), 81-95. doi:10.1002/fam.810080206
• Babrauskas, V. (2016). The cone calorimeter. In SFPE handbook of fire protection engineering (pp. 952-980). New York, USA: Springer. doi:10.1007/978-1-4939-2565-0_26
• Baby, A., Tretsiakova-McNally, S., Arun, M., Joseph, P., & Zhang, J. (2020). Reactive and additive modifications of styrenic polymers with phosphorus-containing compounds and their effects on fire retardance. Molecules, 25(17), 3779. doi:10.3390/molecules25173779
• Bahreyni, E., Farid, M., Fakhari, M. A., & Farid, M. (2017). Synergistic Effect of Intumescent Flame Retardant and Organically Modified Montmorillonite on Flame-Retardant and Foaming Properties of High Density Polyethylene/Walnut Shell Powder Biocomposites . Iranian Journal of Polymer Science & Technology (Persian), 30(4), 299-310. doi:10.22063/jipst.2017.1504
• Betts, K. S. (2008). New thinking on flame retardants. (2008). Environews, 116, 5. doi.org/10.1289/ehp.116-a210
• Bourbigot, S., & Duquesne, S. (2007). Fire retardant polymers: recent developments and opportunities. Journal of Materials Chemistry, 17(22), 2283-2300. doi:10.1039/B702511D
• Chattopadhyay, D. K., & Webster, D. C. (2009). Thermal stability and flame retardancy of polyurethanes. Progress in Polymer Science, 34(10), 1068-1133. doi:10.1016/j.progpolymsci.2009.06.002
• Chiu, Y. S., Jiang, M. D., & Liu, Y. L. (2002). U.S. Patent No. 6,441,067. Washington, DC: U.S. Patent and Trademark Office.
• Cho, C. S., Fu, S. C., Chen, L. W., & Wu, T. R. (1998). Aryl phosphinate anhydride curing for flame retardant epoxy networks. Polymer International, 47(2), 203-209. doi:10.1002/(SICI)1097-0126(1998100)47:2%3C203::AID-PI55%3E3.0.CO;2-X
• Dasari, A., Yu, Z. Z., Cai, G. P., & Mai, Y. W. (2013). Recent developments in the fire retardancy of polymeric materials. Progress in Polymer Science, 38(9), 1357-1387. doi:10.1016/j.progpolymsci.2013.06.006
• Derouet, D., Morvan, F., & Brosse, J. C. (1996). Chemical modification of epoxy resins by dialkyl (or aryl) phosphates: evaluation of fire behaviour and thermal stability. Journal of Applied Polymer Science, 62(11), 1855-1868. doi:10.1002/(SICI)1097-4628(19961212)62:11%3C1855::AID-APP10%3E3.0.CO;2-Y
• Dewaghe, C., Lew, C. Y., Claes, M., Belgium, S. A., & Dubois, P. (2011). Fire-retardant applications of polymer–carbon nanotubes composites: Improved barrier effect and synergism. In T. McNally & P. Pötschke (Eds.), Polymer–Carbon Nanotube Composites (pp. 718-745). Philadelphia, USA: Woodhead Publishing. https://doi.org/10.1533/9780857091390.3.718
• Dorieh, A., Pour, M. F., Movahed, S. G., Pizzi, A., Selakjani, P. P., Kiamahalleh, M. V., ... & Aghaei, R. (2022). A review of recent progress in melamine-formaldehyde resin based nanocomposites as coating materials. Progress in Organic Coatings, 165, 106768. doi:10.1016/j.porgcoat.2022.106768
• Gao, T. T., Li, Z. W., Yu, L. G., & Zhang, Z. J. (2015). Preparation of zinc hydroxystannate nanocomposites coated by organophosphorus and investigation of their effect on mechanical properties and flame retardancy of poly (vinyl chloride). Research Advances, 5(120), 99291-99298. doi.org/10.1039/C5RA10086K
• Gilman, J. W. (1999). Flammability and thermal stability studies of polymer layered-silicate (clay) nanocomposites. Applied Clay Science, 15(1-2), 31-49. doi:10.1016/S0169-1317(99)00019-8
• Green, J. (1996). Mechanisms for flame retardancy and smoke suppression-a review. Journal of fire Sciences, 14(6), 426-442. doi:10.1177/073490419601400602
• Gu, L., Ge, Z., Huang, M., & Luo, Y. (2015). Halogen‐free flame‐retardant waterborne polyurethane with a novel cyclic structure of phosphorus− nitrogen synergistic flame retardant. Journal of Applied Polymer Science, 132(3), 41288. doi:10.1002/app.41288
• Gu, L., Qiu, C., Qiu, J., Yao, Y., Sakai, E., & Yang, L. (2020). Preparation and characterization of DOPO-functionalized MWCNT and its high flame-retardant performance in epoxy nanocomposites. Polymers, 12(3), 613. doi:10.3390/polym12030613
• Guo, X., Wang, H., Ma, D., He, J., & Lei, Z. (2018). Synthesis of a novel, multifunctional inorganic curing agent and its effect on the flame‐retardant and mechanical properties of intrinsically flame retardant epoxy resin. Journal of Applied Polymer Science, 135(29), 46410. doi:10.1002/app.46410
• Hergenrother, P. M., Thompson, C. M., Smith Jr, J. G., Connell, J. W., Hinkley, J. A., Lyon, R. E., & Moulton, R. (2005). Flame retardant aircraft epoxy resins containing phosphorus. Polymer, 46(14), 5012-5024. doi:10.1016/j.polymer.2005.04.025
• Hirschler, M. M. (2001, June). Fire safety in detention environments. Fire Risk & Hazard Assessment Symposium, Fire Protection Research Foundation.
• Hollingbery, L. A., & Hull, T. R. (2010). The fire retardant behaviour of huntite and hydromagnesite–A review. Polymer Degradation and Stability, 95(12), 2213-2225. doi:10.1016/j.polymdegradstab.2010.08.019
• Horrocks, A. R., & Price, D. (Eds.). (2008). Advances in Fire Retardant Materials. Philadelphia, USA: Woodhead Publishing.
• Hull, T. R., Witkowski, A., & Hollingbery, L. (2011). Fire retardant action of mineral fillers. Polymer Degradation and Stability, 96(8), 1462-1469. doi:10.1016/j.polymdegradstab.2011.05.006
• ISO. (1996). Plastics—Determination of burning behaviour by oxygen index—Part 2: Ambient-temperature test (4589).
• ISO. (2002). Reaction‐to‐fire tests‐Heat release, smoke production and mass loss rate‐Part 1: heat release rate (cone calorimeter method) (5660-1).
• Jawaid, M., Thariq, M., & Saba, N. (Eds.). (2018). Durability and Life Prediction in Biocomposites, Fibre-Reinforced Composites and Hybrid Composites. Philadelphia, USA: Woodhead Publishing.
• Jeng, R. J., Wang, J. R., Lin, J. J., Liu, Y. L., Chiu, Y. S., & Su, W. C. (2001). Flame retardant epoxy polymers using phosphorus‐containing polyalkylene amines as curing agents. Journal of Applied Polymer Science, 82(14), 3526-3538. doi:10.1002/app.2215
• Kamalipour, J., Beheshty, M. H., & Zohurianmehr, M. J. (2020, November). Synthesis and preliminary of new phosphorous-containing flame-retardant hardeners for epoxy resin. 14th International Seminar on Polymer Science and Technology, Tahran, Iran.
• Kamalipour, J., Beheshty, M. H., & Zohuriaan-Mehr, M. J. (2021). Flame retardant compounds for epoxy resins: A review. Iranian Journal of Polymer Science and Technology, 34(1), 3-27. doi:10.22063/jipst.2021.1790
• Kiliaris, P., & Papaspyrides, C. D. (2010). Polymer/layered silicate (clay) nanocomposites: an overview of flame retardancy. Progress in Polymer Science, 35(7), 902-958. doi:10.1016/j.progpolymsci.2010.03.001
• Kim, Y., Lee, S., & Yoon, H. (2021). Fire-safe polymer composites: Flame-retardant effect of nanofillers. Polymers, 13(4), 540. doi:10.3390/polym13040540
• Kozłowski, R., & Władyka‐Przybylak, M. (2008). Flammability and fire resistance of composites reinforced by natural fibers. Polymers for Advanced Technologies, 19(6), 446-453. doi:10.1002/pat.1135
• Kuo, P. L., Wang, J. S., Chen, P. C., & Chen, L. W. (2001). Flame‐retarding materials, 3. Tailor‐made thermal stability epoxy curing agents containing difunctional phosphoric amide groups. Macromolecular Chemistry and Physics, 202(11), 2175-2180. doi:10.1002/1521-3935(20010701)202:11%3C2175::AID-MACP2175%3E3.0.CO;2-U
• La Rosa, A. D., Recca, A., Carter, J. T., & McGrail, P. T. (1999). An oxygen index evaluation of flammability on modified epoxy/polyester systems. Polymer, 40(14), 4093-4098. doi:10.1016/S0032-3861(98)00646-6
• Levchik, S. V., Camino, G., Luda, M. P., Costa, L., Costes, B., Henry, Y., ... & Morel, E. (1995). Mechanistic study of thermal behaviour and combustion performance of epoxy resins. II. TGDDM/DDS system. Polymer Degradation and Stability, 48(3), 359-370. doi:10.1016/0141-3910(95)00084-Y
• Levchik, S. V., & Weil, E. D. (2004). Thermal decomposition, combustion and fire‐retardancy of polyurethanes—a review of the recent literature. Polymer International, 53(11), 1585-1610. doi:10.1002/pi.1314
• Levchik, S., Piotrowski, A., Weil, E., & Yao, Q. (2005). New developments in flame retardancy of epoxy resins. Polymer Degradation and Stability, 88(1), 57-62. doi:10.1016/j.polymdegradstab.2004.02.019
• Levinta, N., Corobea, M. C., Vuluga, Z., Nicolae, C. A., Gabor, A. R., Raditoiu, V., ... & Teodorescu, M. (2020). Bio-based polyamide 1010 with a halogen-free flame retardant based on melamine–gallic acid complex. Polymers, 12(7), 1482. doi:10.3390/polym12071482
• Li, G., Wang, W., Cao, S., Cao, Y., & Wang, J. (2014). Reactive, intumescent, halogen‐free flame retardant for polypropylene. Journal of Applied Polymer Science, 131(7), 40054. doi:10.1002/app.40054
• Liu, X., & Liang, B. (2017). Impact of a novel phosphorus-nitrogen flame retardant curing agent on the properties of epoxy resin. Materials Research Express, 4(12), 125103. doi:10.1088/2053-1591/aa9dba
• Lu, S. Y., & Hamerton, I. (2002). Recent developments in the chemistry of halogen-free flame retardant polymers. Progress in Polymer Science, 27(8), 1661-1712. doi:10.1016/S0079-6700(02)00018-7
• Luhar, S., Nicolaides, D., & Luhar, I. (2021). Fire resistance behaviour of geopolymer concrete: An overview. Buildings, 11(3), 82. doi:10.3390/buildings11030082
• Marti, J., Idelsohn, S. R., & Oñate, E. (2018). A finite element model for the simulation of the UL-94 burning test. Fire Technology, 54(6), 1783-1805. doi:10.1007/s10694-018-0769-0
• Mozaffari, S. M., & Beheshty, M. H. (2018). Thermally-latent curing agents for epoxy resins: a review. Iranian Journal of Polymer Science and Technology, 31(5), 409-426. doi:10.22063/jipst.2019.1610
• Javid, M., & Thariq, M. (2018). Sustainable Composites for Aerospace Applications. Woodhead Publishing Series in Composites Science and Engineering, 1, 109-123.
• Niazi, M., & Beheshty, M. H. (2019). A new latent accelerator and study of its effect on physical, mechanical and shelf-life of carbon fiber epoxy prepreg. Iranian Polymer Journal, 28(4), 337-346. doi:10.1007/s13726-019-00704-8
• Pecht, M., & Deng, Y. (2006). Electronic device encapsulation using red phosphorus flame retardants. Microelectronics Reliability, 46(1), 53-62. doi:10.1016/j.microrel.2005.09.001
• Qian, X., Song, L., Bihe, Y., Yu, B., Shi, Y., Hu, Y., & Yuen, R. K. (2014). Organic/inorganic flame retardants containing phosphorus, nitrogen and silicon: Preparation and their performance on the flame retardancy of epoxy resins as a novel intumescent flame retardant system. Materials Chemistry and Physics, 143(3), 1243-1252. doi:10.1016/j.matchemphys.2013.11.029
• Rahimi-Aghdam, T., & Shariatinia, Z. (2018). Flame retardancy in polymeric materials: A short overview. Basparesh, 7(4), 38-47. doi:10.22063/BASPARESH.2017.1510
• Ray, S. S., & Okamoto, M. (2003). Polymer/layered silicate nanocomposites: a review from preparation to processing. Progress in Polymer Science, 28(11), 1539-1641. doi:10.1016/j.progpolymsci.2003.08.002
• Rothon, R. N., & Hornsby, P. R. (1996). Flame retardant effects of magnesium hydroxide. Polymer Degradation and Stability, 54(2-3), 383-385. doi:10.1016/S0141-3910(96)00067-5
• Salmeia, K. A., & Gaan, S. (2015). An overview of some recent advances in DOPO-derivatives: Chemistry and flame retardant applications. Polymer Degradation and Stability, 113, 119-134. doi:10.1016/j.polymdegradstab.2014.12.014
• Serbezeanu, D., Vlad-Bubulac, T., Hamciuc, E., Hamciuc, C., Lisa, G., Anghel, I., … & Preda, D-M. (2021). Study on thermal and flame retardant properties of phosphorus-containing polyimides. Revista de Chimie, 72(4), 13-21. doi:10.37358/RC.21.4.8452
• Schartel, B. (2010). Phosphorus-based flame retardancy mechanisms—old hat or a starting point for future development?. Materials, 3(10), 4710-4745. doi:10.3390/ma3104710
• Sonnier, R., Dumazert, L., Livi, S., Nguyen, T. K. L., Duchet-Rumeau, J., Vahabi, H., & Laheurte, P. (2016). Flame retardancy of phosphorus-containing ionic liquid based epoxy networks. Polymer Degradation and Stability, 134, 186-193. doi:10.1016/j.polymdegradstab.2016.10.009
• Trigo-López, M., Sanjuán, A. M., Mendía, A., Muñoz, A., García, F. C., & García, J. M. (2020). Heteroaromatic polyamides with improved thermal and mechanical properties. Polymers, 12(8), 1793. doi:10.3390/polym12081793
• Ullah, S., Bustam, M. A., Nadeem, M., Naz, M. Y., Tan, W. L., & Shariff, A. M. (2014). Synthesis and thermal degradation studies of melamine formaldehyde resins. The Scientific World Journal, 2014, 940502. doi:10.1155/2014/940502
• Van der Veen, I., & de Boer, J. (2012). Phosphorus flame retardants: properties, production, environmental occurrence, toxicity and analysis. Chemosphere, 88(10), 1119-1153. doi:10.1016/j.chemosphere.2012.03.067
• Varma, I. K., & Gupta, U. (1986). Curing of epoxy resin with phosphorylated diamine. Journal of Macromolecular Science: Part A - Chemistry, 23(1), 19-36. doi:10.1080/00222338608063373
• Walters, R. N., & Lyon, R. E. (2008). Flammability of polymer composites. Washington, DC, USA: Office of aviation research and development, federal aviation administration.
• Wang, C. S., Berman, J. R., Walker, L. L., & Mendoza, A. (1991). Meta‐bromobiphenol epoxy resins: Applications in electronic packaging and printed circuit board. Journal of Applied Polymer Science, 43(7), 1315-1321. doi:10.1002/app.1991.070430713
• Wang, C. S., & Shieh, J. Y. (1999). Phosphorus‐containing epoxy resin for an electronic application. Journal of Applied Polymer Science, 73(3), 353-361. doi:10.1002/(SICI)1097-4628(19990718)73:3%3C353::AID-APP6%3E3.0.CO;2-V
• Wang, C. S., & Lin, C. H. (1999a). Properties and curing kinetic of diglycidyl ether of bisphenol A cured with a phosphorus‐containing diamine. Journal of Applied Polymer Science, 74(7), 1635-1645. doi:10.1002/(SICI)1097-4628(19991114)74:7%3C1635::AID-APP4%3E3.0.CO;2-P
• Wang, C. S., & Lin, C. H. (1999b). Synthesis and properties of phosphorus‐containing epoxy resins by novel method. Journal of Polymer Science Part A: Polymer Chemistry, 37(21), 3903-3909. doi:10.1002/(SICI)1099-0518(19991101)37:21%3C3903::AID-POLA4%3E3.0.CO;2-X
• Wang, C. S., & Lee, M. C. (2000). Synthesis and properties of epoxy resins containing 2-(6-oxid-6H-dibenz (c, e)(1, 2) oxaphosphorin-6-yl) 1, 4-benzenediol (II). Polymer, 41(10), 3631-3638. doi:10.1016/S0032-3861(99)00541-8
• Wang, C. S., & Lin, C. H. (2000). Synthesis and properties of phosphorus containing advanced epoxy resins. Journal of Applied Polymer Science, 75(3), 429-436. doi:10.1002/(SICI)1097-4628(20000118)75:3%3C429::AID-APP13%3E3.0.CO;2-U
• Weil, E. D., & Levchik, S. (2004). A review of current flame retardant systems for epoxy resins. Journal of Fire Sciences, 22(1), 25-40. doi:10.1177/0734904104038107
• Wu, X., Dong, C., Wirasaputra, A., Huang, H., Liu, S., Zhao, J., & Fu, Y. (2018). Imparting high flame retardancy to epoxy resin with ultra-low loading of 5, 10-dihydro-phenophosphazine-10-oxide functioned triazine. High Performance Polymers, 30(6), 742-751. doi:10.1177/0954008317723083
• Xiong, Y. Q., Zhang, X. Y., Liu, J., Li, M. M., Guo, F., Xia, X. N., & Xu, W. J. (2012). Synthesis of novel phosphorus‐containing epoxy hardeners and thermal stability and flame‐retardant properties of cured products. Journal of Applied Polymer Science, 125(2), 1219-1225. doi:10.1002/app.34894
• Xiao, Y., Zheng, Y., Wang, X., Chen, Z., & Xu, Z. (2014). Preparation of a chitosan‐based flame‐retardant synergist and its application in flame‐retardant polypropylene. Journal of Applied Polymer Science, 131(19), 40845. doi:10.1002/app.40845
• Xu, M., Zhao, W., & Li, B. (2014). Synthesis of a novel curing agent containing organophosphorus and its application in flame‐retarded epoxy resins. Journal of Applied Polymer Science, 131(23), 41159. doi:10.1002/app.41159
• Xu, Q., Chen, L., Harries, K. A., Zhang, F., Liu, Q., & Feng, J. (2015). Combustion and charring properties of five common constructional wood species from cone calorimeter tests. Construction and Building Materials, 96, 416-427. doi:10.1016/j.conbuildmat.2015.08.062
• Xu, Y. J., Wang, J., Tan, Y., Qi, M., Chen, L., & Wang, Y. Z. (2018). A novel and feasible approach for one-pack flame-retardant epoxy resin with long pot life and fast curing. Chemical Engineering Journal, 337, 30-39. doi:10.1016/j.cej.2017.12.086
• Zhao, Q., Chen, C., Fan, R., Yuan, Y., Xing, Y., & Ma, X. (2017). Halogen-free flame-retardant rigid polyurethane foam with a nitrogen–phosphorus flame retardant. Journal of Fire Sciences, 35(2), 99-117. doi:10.1177/0734904116684363
• Zhou, T., He, X., Guo, C., Yu, J., Lu, D., & Yang, Q. (2015). Synthesis of a novel flame retardant phosphorus/nitrogen/siloxane and its application on cotton fabrics. Textile Research Journal, 85(7), 701-708. doi:10.1177/0040517514555801
• Zhang, Y. F., Liu, J. Z., Li, J., Wang, C. Y., & Ren, Q. (2022). Synthesis and storage stability investigation on curing agent microcapsules of imidazole derivatives with aqueous polyurethane as the shell. Polymer Bulletin, 79, 10295-10311. doi:10.1007/s00289-021-04063-4
• Zhong, Y., Wu, W., Lin, X., & Li, M. (2014). Flame‐retarding mechanism of organically modified montmorillonite and phosphorous‐Nitrogen flame retardants for the preparation of a halogen‐free, flame‐retarding thermoplastic poly (ester ether) elastomer. Journal of Applied Polymer Science, 131(22), 41094. doi:10.1002/app.41094