Abstract
In this study, organic–inorganic-modified ammonium polyphosphate (APP) flame retardant (FR) was prepared by a sol–gel method that used tetraethoxysilane and vinyltriethoxysilane as precursors. Then modified APP (VTSAPP) was added into polyurethane (PU) to fabricate the FR PU/VTSAPP composites. Crucially, the structure and performance of VTSAPP were systematically characterized. The results showed that a dense hybrid silica gel layer structure was formed on the surface of APP. Ideally, the limiting oxygen index (LOI) value of PU/20VTSAPP composite increased from 19.5% for pure PU to 30% and the vertical burning test (UL-94) reached up to V-0 level. Moreover, the addition of VTSAPP dramatically decreased the released smoke of PU during combustion compared to the counterpart of APP. The FR mechanism of VTSAPP was deeply explored. It is confidently shown that phosphorus and silicon compounds of VTSAPP contributed to the formation of a more continuous and compact char and improved the thermal stability of the char layer. The results of this study distinctly confirmed that VTSAPP was an effective FR agent for PU.
Highlights
-
The modified APP flame retardant was prepared by a sol–gel method that used TEOS and VTES as precursors.
-
The modified APP was added into the PU matrix to prepared flame-retardant PU composites.
-
The modified APP not only enhanced the flame retardancy of PU but also reduced the smoke emission.
-
The flame-retardant mechanism of modified APP in PU was deeply explored.
Similar content being viewed by others
References
Cornille A, Auvergne R, Figovsky O, Boutevin B, Caillol S (2017) A perspective approach to sustainable routes for non-isocyanate polyurethanes. Eur Polym J 87:535–552. https://doi.org/10.1016/j.eurpolymj.2016.11.027
Chattopadhyay DK, Raju KVSN (2007) Structural engineering of polyurethane coatings for high performance applications. Prog Polym Sci 32(3):352–418. https://doi.org/10.1016/j.progpolymsci.2006.05.003
Akindoyo JO, Beg MDH, Ghazali S, Islam MR, Jeyaratnam N, Yuvaraj AR (2016) Polyurethane types, synthesis and applications—a review. Rsc Adv 6(115):114453–114482. https://doi.org/10.1039/c6ra14525f
Visakh PM, Semkin AO, Rezaev IA, Fateev AV (2019) Review on soft polyurethane flame retardant. Constr Build Mater 227. https://doi.org/10.1016/j.conbuildmat.2019.116673
Huang SC, Deng C, Wang SX, Wei WC, Chen H, Wang YZ (2019) Electrostatic action induced interfacial accumulation of layered double hydroxides towards highly efficient flame retardance and mechanical enhancement of thermoplastic polyurethane/ammonium polyphosphate. Polym Degrad Stab 165:126–136. https://doi.org/10.1016/j.polymdegradstab.2019.05.006
Liu LB, Xu Y, Li S, Xu MJ, He YT, Shi ZX, Li B (2019) A novel strategy for simultaneously improving the fire safety, water resistance and compatibility of thermoplastic polyurethane composites through the construction of biomimetic hydrophobic structure of intumescent flame retardant synergistic system. Compos B Eng 176. https://doi.org/10.1016/j.compositesb.2019.107218
Yu SW, Xiao SJ, Zhao ZW, Huo XW, Wei JF (2019) Microencapsulated ammonium polyphosphate by polyurethane with segment of dipentaerythritol and its application in flame retardant polypropylene. Chin J Chem Eng 27(7):1735–1743. https://doi.org/10.1016/j.cjche.2019.04.023
Zhang Y, Hu YX, Wang JL, Tian WX, Liew KM, Zhang Y, Wang BB (2018) Engineering carbon nanotubes wrapped ammonium polyphosphate for enhancing mechanical and flame retardant properties of poly(butylene succinate). Compos A Appl Sci Manuf 115:215–227. https://doi.org/10.1016/j.compositesa.2018.09.020
Zhang S, Ji WF, Han Y, Gu XY, Li HF, Sun J (2018) Flame-retardant expandable polystyrene foams coated with ethanediol-modified melamine-formaldehyde resin and microencapsulated ammonium polyphosphate. J Appl Polym Sci 135(28). https://doi.org/10.1002/app.46471
Li QM, Wang JY, Chen LM, Shi H, Hao JW (2019) Ammonium polyphosphate modified with beta-cyclodextrin crosslinking rigid polyurethane foam: enhancing thermal stability and suppressing flame spread. Polym Degrad Stab 161:166–174. https://doi.org/10.1016/j.polymdegradstab.2019.01.024
Kim M, Ko H, Park SM (2019) Synergistic effects of amine-modified ammonium polyphosphate on curing behaviors and flame retardation properties of epoxy composites. Compos B Eng 170:19–30. https://doi.org/10.1016/j.compositesb.2019.04.016
Qi C, Yuan B, Dong H, Li K, Shang S, Sun Y, Chen G, Zhan Y (2020) Supramolecular self‐assembly modification of ammonium polyphosphate and its flame retardant application in polypropylene. Polym Adv Technol 31(5):1099–1109. https://doi.org/10.1002/pat.4844
Liu JC, Xu MJ, Lai T, Li B (2015) Effect of surface-modified ammonium polyphosphate with KH550 and SIlicon Resin on the Flame Retardancy, Water Resistance, Mechanical and Thermal Properties of Intumescent Flame Retardant Polypropylene. Ind Eng Chem Res 54(40):9733–9741. https://doi.org/10.1021/acs.iecr.5b01670
Deng CL, Du SL, Zhao J, Shen ZQ, Deng C, Wang YZ (2014) An intumescent flame retardant polypropylene system with simultaneously improved flame retardancy and water resistance. Polym Degrad Stab 108:97–107. https://doi.org/10.1016/j.polymdegradstab.2014.06.008
Li RM, Deng C, Deng CL, Dong LP, Di HW, Wang YZ (2015) An efficient method to improve simultaneously the water resistance, flame retardancy and mechanical properties of POE intumescent flame-retardant systems. RSC Adv 5(21):16328–16339. https://doi.org/10.1039/c4ra15971c
Hoang DT, Schorr D, Landry V, Blanchet P, Vanslambrouck S, Dagenais C (2018) Preparation and characterisation of flame retardant encapsulated with functionalised silica-based shell. J Microencapsul 35(5):428–438. https://doi.org/10.1080/02652048.2018.1521477
Gao WY, Qian XD, Wang SJ (2018) Preparation of hybrid silicon materials microcapsulated ammonium polyphosphate and its application in thermoplastic polyurethane. J Appl Polym Sci 135(4). https://doi.org/10.1002/app.45742
Qu HQ, Wu WH, Hao JW, Wang CZ, Xu JZ (2014) Inorganic-organic hybrid coating-encapsulated ammonium polyphosphate and its flame retardancy and water resistance in epoxy resin. Fire Mater 38(3):312–322. https://doi.org/10.1002/fam.2182
Ran GW, Liu XD, Guo J, Sun J, Li HF, Gu XY, Zhang S (2019) Improving the flame retardancy and water resistance of polylactic acid by introducing polyborosiloxane microencapsulated ammonium polyphosphate. Compos B Eng 173. https://doi.org/10.1016/j.compositesb.2019.04.033
Chen YJ, Li LS, Qi XQ, Qian LJ (2019) The pyrolysis behaviors of phosphorus-containing organosilicon compound modified APP with different polyether segments and their flame retardant mechanism in polyurethane foam. Compos B Eng 173. https://doi.org/10.1016/j.compositesb.2019.04.045
Chen YJ, Li LS, Xu LF, Qian LJ (2018) Phosphorus-containing silica gel-coated ammonium polyphosphate: preparation, characterization, and its effect on the flame retardancy of rigid polyurethane foam. J Appl Polym Sci 135(22). https://doi.org/10.1002/app.46334
Ni JX, Chen LJ, Zhao KM, Hu Y, Song L (2011) Preparation of gel-silica/ammonium polyphosphate core-shell flame retardant and properties of polyurethane composites. Polym Adv Technol 22(12):1824–1831. https://doi.org/10.1002/pat.1679
Qin ZL, Yang RJ, Zhang WC, Li DH, Jiao QJ (2019) Synergistic barrier effect of aluminum phosphate on flame retardant polypropylene based on ammonium polyphosphate/dipentaerythritol system. Mater Design 181. https://doi.org/10.1016/j.matdes.2019.107913
Zhang Y, Wang BB, Sheng HB, Yuan BH, Yu B, Tang G, Jie GX, Feng H, Tao YJ, Hu Y (2016) Enhanced fire-retardancy of poly(ethylene vinyl acetate) electrical cable coatings containing microencapsulated ammonium polyphosphate as intumescent flame retardant. RSC Adv 6(88):85564–85573. https://doi.org/10.1039/c6ra15314c
Qin ZL, Li DH, Zhang WC, Yang RJ (2015) Surface modification of ammonium polyphosphate with vinyltrimethoxysilane: Preparation, characterization, and its flame retardancy in polypropylene. Polym Degrad Stab 119:139–150. https://doi.org/10.1016/j.polymdegradstab.2015.05.012
Yang AH, Deng C, Chen H, Wei YX, Wang YZ (2017) A novel Schiff-base polyphosphate ester: highly-efficient flame retardant for polyurethane elastomer. Polym Degrad Stab 144:70–82. https://doi.org/10.1016/j.polymdegradstab.2017.08.007
Tan Y, Shao ZB, Chen XF, Long JW, Chen L, Wang YZ (2015) Novel multifunctional organic-inorganic hybrid curing agent with high flame-retardant efficiency for epoxy resin. ACS Appl Mater Inter 7(32):17919–17928. https://doi.org/10.1021/acsami.5b04570
Yang W, Lu HD, Tai QL, Qiao ZH, Hu Y, Song L, Yuen RKK (2011) Flame retardancy mechanisms of poly(1,4-butylene terephthalate) containing microencapsulated ammonium polyphosphate and melamine cyanurate. Polym Adv Technol 22(12):2136–2144. https://doi.org/10.1002/pat.1735
Matar M, Azambre B, Cochez M, Vahabi H, Fradet F (2016) Influence of modified mesoporous silica SBA-15 on the flammability of intumescent high-density polyethylene. Polym Adv Technol 27(10):1363–1375. https://doi.org/10.1002/pat.3805
Acknowledgements
The authors are grateful to the Zhejiang Sci-Tech University and Zhejiang Provincial Key Lab of Industrial Textile Materials & Manufacturing Tech for financial support of this research.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare no competing interests.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Zeng, F., Zhao, Y., Meng, Y. et al. Study on sol–gel-modified ammonium polyphosphate and its application in the flame-retardant polyurethane composites. J Sol-Gel Sci Technol 98, 615–626 (2021). https://doi.org/10.1007/s10971-021-05526-w
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10971-021-05526-w