Owing to the superior thermal insulating attributes of rigid polyurethane foam (RPUF) compared to other insulating materials (expanded and extruded polystyrene, mineral wool), it remains the most dominant insulating material and most studied polymer foam. Like other polyurethane foam, RPUF is highly flammable, necessitating the incorporation of flame retardants (FR) during production to lower combustibility, promoting its continuous use as insulation material in construction, transportation, and others. The popular approaches for correcting the high flammability of RPUF are copolymerization and blending (with FR). The second method has proven to be most effective as there are limited trade-offs in RPUF properties. Meanwhile, the high flammability of RPUF is still a significant hindrance in emerging applications (sensors, space travel, and others), and this has continuously inspired research in the flame retardancy of RPUF. In this study, properties, and preparation methods of RPUF are described, factors responsible for the high flammability of PUF are discussed, and flame retardancy of RPUF is thoroughly reviewed. Notably, most FR for RPUF are inorganic nanoparticles, lignin, intumescent FR systems of expandable graphite (EG), ammonium polyphosphate (APP), and hybridized APP or EG with other FR. These could be due to their ease of processing, low cost, and being environmentally benign. Elaborate discussion on RPUF FR mechanisms were also highlighted. Lastly, a summary and future perspectives in fireproofing RPUF are provided, which could inspire the design of new FR for RPUF.
KausarA. Polyurethane composite foams in high performance applications: A Rev2018; 57: 346–369.
3.
Abu-JdayilBMouradAHHittiniW, et al.Traditional, state-of-the-art and renewable thermal building insulation materials: an overview. Construction Building Mater2019; 214: 709–735.
LiuCFangYMiaoX, et al.Facile fabrication of superhydrophobic polyurethane sponge towards oil-water separation with exceptional flame-retardant performance. Sep Purif Technol2019; 229: 115801.
6.
BaguianAFOuimingaSKLonguetC, et al.Influence of density on foam collapse under burning. Polymers (Basel)2021; 23: 1–17.
7.
ShoaibSShahzad MaqsoodKNafisaG, et al.A comprehensive short review on polyurethane foam. Int J Innov Appl Stud2014; 12: 165–169.
KavšekMFigarNMiheličI, et al.Melamine-formaldehyde rigid foams – manufacturing and their thermal insulation properties. J Cell Plast2022; 58: 175–193.
11.
SimónDBorregueroAMde LucasA, et al.Recycling of polyurethanes from laboratory to industry, a journey towards the sustainability. Waste Management2018; 76: 147–171.
12.
SimónDBorregueroAMde LucasA, et al.Glycolysis of viscoelastic flexible polyurethane foam wastes. Polym Degrad Stab2015; 116: 23–35.
13.
ShengMWuLLiX, et al.Preparation and characterization of super-toughened PLA/CPU blends via one-step dynamic vulcanization. Eng Sci2021; 19: 89–99.
14.
ZouWHuangJZengW, et al.Effect of ethylene–butylacrylate–glycidyl methacrylate on compatibility properties of poly (butylene terephthalate)/thermoplastic polyurethane blends. ES Energy Environ2020; 9: 67–73.
15.
SangGXuPYanT, et al.Interface engineered microcellular magnetic conductive polyurethane nanocomposite foams for electromagnetic interference shielding. Nano-micro Lett2021; 13: 1–16.
16.
GaoQPanYZhengG, et al.Flexible multilayered MXene/thermoplastic polyurethane films with excellent electromagnetic interference shielding, thermal conductivity, and management performances. Adv Compos Hybrid Mater2021; 4: 274–285.
17.
YuanHPanYWangX, et al.Simple water tunable polyurethane microsphere for super-hydrophobic dip-coating and oil-water separation. Polymer (Guildf)2020; 204: 122833.
18.
SongHZhangQZhangY, et al.Waterborne polyurethane/3-amino-polyhedral oligomeric silsesquioxane (NH2-POSS) nanocomposites with enhanced properties. Adv Compos Hybrid Mater2021; 4: 629–638.
19.
LiuCYinQLiX, et al.A waterborne polyurethane–based leather finishing agent with excellent room temperature self-healing properties and wear-resistance. Adv Compos Hybrid Mater2021; 4: 138–149.
20.
WangXFXKalaliENWanJT, et al.Coated vs. naked red phosphorus: a comparative study on their fire retardancy and smoke suppression for rigid polyurethane foams. Polym Degrad Stab2014; 97: 751–824.
21.
SchiavoniSD’AlessandroFBianchiF, et al.Insulation materials for the building sector: a review and comparative analysis. Renew Sustainable Energy Rev2016; 62: 988–1011.
22.
WangLTawiahBShiY, et al.Highly effective flame-retardant rigid polyurethane foams: Fabrication and applications in inhibition of coal combustion. Polymers (Basel); 11: 1776. DOI: 10.3390/polym11111776
23.
ElingBTomovićŽSchädlerV. Current and future trends in polyurethanes: an industrial perspective. Macromol Chem Phys2020; 221: 2000114.
24.
GavganiJNAdelniaHGudarziMM. Intumescent flame retardant polyurethane/reduced graphene oxide composites with improved mechanical, thermal, and barrier properties. J Mater Sci2014; 49: 243–254.
25.
TiucAENemeşOVermeşanH, et al.New sound absorbent composite materials based on sawdust and polyurethane foam. Compos Part B Eng2019; 165: 120–130.
26.
JiangDWangYLiB, et al.Environmentally friendly alternative to polyester polyol by corn straw on preparation of rigid polyurethane composite. Compos Commun2020; 17: 109–114.
27.
GaoLZhengGZhouY, et al.Synergistic effect of expandable graphite, melamine polyphosphate and layered double hydroxide on improving the fire behavior of rosin-based rigid polyurethane foam. Ind Crops Prod2013; 50: 638–647.
28.
LiuXHaoJGaanS. Recent studies on the decomposition and strategies of smoke and toxicity suppression for polyurethane based materials. RSC Adv2016; 6: 74742–74756.
29.
ZieleniewskaMLeszczyńskiMKKurańskaM, et al.Preparation and characterisation of rigid polyurethane foams using a rapeseed oil-based polyol. Ind Crops Prod2015; 74: 887–897.
30.
JonjaroenVUmmartyotinSChittapunS. Algal cellulose as a reinforcement in rigid polyurethane foam. Algal Res2020; 51: 102057.
31.
JelleBP. Traditional, state-of-the-art and future thermal building insulation materials and solutions - Properties, requirements and possibilities. Energy Build2011; 43: 2549–2563.
32.
BanikISainMM. Water blown soy polyol-based polyurethane foams of different rigidities. J Reinf Plast Compos2008; 27: 357–373.
33.
JiaoLXiaoHWangQ, et al.Thermal degradation characteristics of rigid polyurethane foam and the volatile products analysis with TG-FTIR-MS. Polym Degrad Stab2013; 98: 2687–2696.
34.
AkindoyoJOBegMDHGhazaliS, et al.Polyurethane types, synthesis and applications-a review. RSC Adv2016; 6: 114453–114482.
35.
ChenHLuHZhouY, et al.Study on thermal properties of polyurethane nanocomposites based on organo- sepiolite. Polym Degrad Stab2012; 97: 242–247.
36.
GaoMLiJZhouX. A flame retardant rigid polyurethane foam system including functionalized graphene oxide. Polym Compos2019; 40: E1274–E1282.
37.
AbiSalehTAndersonMBarkerM, et al.Introduction to polyurethanes. In: DRS.Lee (eds) The polyurethanes book. New York: Wiley, 2003, pp. 1–8.
38.
Nik Pauzi NNPAMajidRDzulkifliMH, et al.Development of rigid bio-based polyurethane foam reinforced with nanoclay. Compos Part B Eng2014; 67: 521–526.
39.
ShiXJiangSZhuJ, et al.Establishment of a highly efficient flame-retardant system for rigid polyurethane foams based on bi-phase flame-retardant actions. RSC Adv2018; 8: 9985–9995.
40.
SonnenscheinMF. POLYURETHANES - science, technology, markets, and trends. New Jersey: Wiley, 2015.
41.
LeeSTRameshNS. Polymeric foams: mechanisms and materials. 2004.
42.
KimYHLeeJWChoiSJ, et al.Properties of rigid polyurethane foams blown by HFC-365 mfc and distilled water. J Ind Eng Chem2007; 13: 1076–1082.
43.
LiJMoXLiY, et al.Influence of expandable graphite particle size on the synergy flame retardant property between expandable graphite and ammonium polyphosphate in semi-rigid polyurethane foam. Polym Bull2018; 75: 5287–5304.
44.
KirpluksMCabulisUZeltinsV, et al.Rigid polyurethane foam thermal insulation protected with mineral intumescent mat. Autex Res J2014; 14: 259–269.
45.
AkdoganEErdemMUreyenM, et al.Rigid polyurethane foams with halogen-free flame retardants: Thermal insulation, mechanical, and flame retardant properties. J Appl Polym Sci; 137: 47611. DOI: 10.1002/app.47611
46.
CaoZLiaoWWangS, et al.Polyurethane foams with functionalized graphene towards high fire-resistance, low smoke release, superior thermal insulation. Chem Eng J2019; 361: 1245–1254.
47.
SzycherM. Handbook of polyurethanes. Boca Raton, 2013. Epub ahead of print 2013. DOI: 10.1038/142853a0
48.
CabulisUKirpluksMStirnaU, et al.Rigid polyurethane foams obtained from tall oil and filled with natural fibers: application as a support for immobilization of lignin-degrading microorganisms. J Cell Plast2012; 48: 500–515.
49.
ChattopadhyayDKWebsterDC. Thermal stability and flame retardancy of polyurethanes. Prog Polym Sci2009; 34: 1068–1133.
50.
CiecierskaEJurczyk-KowalskaMBazarnikP, et al.Flammability, mechanical properties and structure of rigid polyurethane foams with different types of carbon reinforcing materials. Compos Struct2016; 140: 67–76.
51.
ChingYCChuahCHChingKY, et al.Applications of thermoplastic-based blends. 2017: Elsevier. 111–129. DOI: 10.1016/B978-0-08-100408-1.00005-4
52.
ZengS-LXingC-YChenL, et al.Green flame-retardant flexible polyurethane foam based on cyclodextrin. Polym Degrad Stab2020; 178: 109171.
53.
FengYHeCWenY, et al.Superior flame retardancy and smoke suppression of epoxy-based composites with phosphorus/nitrogen co-doped graphene. J Hazard Mater2018; 346: 140–151.
XiWQianLChenY, et al.Addition flame-retardant behaviors of expandable graphite and [bis(2-hydroxyethyl)amino]-methyl-phosphonic acid dimethyl ester in rigid polyurethane foams. Polym Degrad Stab2015; 122: 36–43.
56.
UllahSShariffABustamM, et al.Effects of ammonium polyphosphate and boric acid on the thermal degradation of an intumescent fire retardant coating. Prog Org Coat; 109: 70–82. DOI: 10.1016/j.porgcoat.2017.04.017
57.
CzłonkaSStrąkowskaAStrzelecK, et al.Melamine, silica, and ionic liquid as a novel flame retardant for rigid polyurethane foams with enhanced flame retardancy and mechanical properties. Polym Test; 87: 106511. DOI: 10.1016/j.polymertesting.2020.106511
58.
LiuQGaoSZhaoY, et al.Review of layer-by-layer self-assembly technology for fire protection of flexible polyurethane foam. J Mater Sci2021; 56: 9605–9643. DOI: 10.1007/s10853-021-05904-3
VisakhPMSemkinAORezaevIA, et al.Review on soft polyurethane flame retardant. Constr Build Mater2019; 227: 116673.
61.
YangHYuBSongP, et al.Surface-coating engineering for flame retardant flexible polyurethane foams: a critical review. Compos Part B2019; 176: 107185.
62.
YangCFischerLMarandaS, et al.Rigid polyurethane foams incorporated with phase change materials: a state-of-the-art review and future research pathways. Energy Build2015; 87: 25–36.
63.
MahmoodNYuanZSchmidtJ, et al.Depolymerization of lignins and their applications for the preparation of polyols and rigid polyurethane foams: a review. Renew Sustainable Energy Rev2016; 60: 317–329.
64.
EngelsHWPirklHGAlbersR, et al.Polyurethanes: versatile materials and sustainable problem solvers for today’s challenges. Angew Chem - Int Edition2013; 52: 9422–9441.
65.
CharlonMHeinrichBMatterY, et al.Synthesis, structure and properties of fully biobased thermoplastic polyurethanes, obtained from a diisocyanate based on modified dimer fatty acids, and different renewable diols. Eur Polym J2014; 61: 197–205.
SarafVPGlasserWG. Engineering plastics from lignin. III. Structure property relationships in solution cast polyurethane films. J Appl Polym Sci1984; 29: 1831–1841.
68.
JavniIZhangWPetrovićZS. Effect of different isocyanates on the properties of soy-based polyurethanes. J Appl Polym Sci2003; 88: 2912–2916.
69.
KappsMBuschkampS. The production of rigid polyurethane foam. Bayer Mater Sci2004; 20: 3–12.
70.
EavesD. Polymer foams - trends in use and technology.Shropshire: Rapra Technology Ltd, 2001.
71.
LiY. Application of cellulose nanowhiskers and lignin in preparation of rigid PUR Nanocomposite foams. PhD Thesis. Georgia, United States: Georgia Institute of Technology, 2012.
72.
IvdreAAbolinsASevastyanovaI, et al.Rigid polyurethane foams with various isocyanate indices based on polyols from rapeseed oil and waste PET. Polymers (Basel)2020; 12: 738.
73.
KimSHKimBKLimH. Effect of isocyanate index on the properties of rigid polyurethane foams blown by HFC 365mfc. Macromol Res2008; 16: 467–472.
74.
MartinDJMeijsGFRenwickGM, et al.The effect of average soft segment length on morphology and properties of a series of polyurethane elastomers. I. Characterization of the series. J Appl Polym Sci1996; 62: 1377–1386.
75.
GisselfältKHelgeeB. Effect of soft segment length and chain extender structure on phase separation and morphology in poly(urethane urea)s. Macromol Mater Eng2003; 288: 265–271.
VeroneseVBMengerRKForteMM de C, et al.Rigid polyurethane foam based on modified vegetable oil. J Appl Polym Sci2011; 120: 530–537.
78.
WangS-XZhaoH-BRaoW-H, et al.Inherently flame-retardant rigid polyurethane foams with excellent thermal insulation and mechanical properties. Polymer (Guildf)2018; 153: 616–625.
79.
YurtsevenR.Effects of ammonium polyphosphate/melamine additions on mechanical, thermal and burning properties of rigid polyurethane foams. Acta Phys Pol A2019; 135: 775–777.
80.
SrihanumATuan NoorMTIDeviKPP, et al.Low density rigid polyurethane foam incorporated with renewable polyol as sustainable thermal insulation material. J Cell Plast2022; 0021955X2110626.
81.
I.R. C.Castable polyurethane elastomers. New York: CRC Press, 2008.
82.
YaziciM. A novel high strain rate sensitive rigid polyurethane resin based syntactic foam. Acta Phys Pol A2016; 129: 613–616.
83.
ChauKWGeilPH. Domain morphology in polyurethanes. 26th ed.London: Butterworth, 1985.
84.
ShufenLZhiJKaijunY, et al.Studies on the thermal behavior of polyurethanes. Polym Plast Technol Eng2006; 45: 95–108.
85.
SeguraDMNurseADMcCourtA, et al.Handbook of adhesive and sealants. Elsevier, 2005.
86.
LemKWLeeDSHawJR, et al.Effect of hard segment molecular weight on dilute solution properties of ether based thermoplastic polyurethanes. Polymer (Guildf)2011; 1: 624–627.
87.
YangLTZhaoCSDaiCL, et al.Thermal and mechanical properties of polyurethane rigid foam based on epoxidized soybean oil. J Polym Environ2012; 20: 230–236.
88.
ChattopadhyayDKRajuKVSN. Structural engineering of polyurethane coatings for high performance applications. Prog Polym Sci (Oxford)2007; 32: 352–418.
89.
KuranchieCYayaABensahYD. The effect of natural fibre reinforcement on polyurethane composite foams – a review. Sci Afr2021; 11: e00722.
90.
GuRSainMM. Effects of wood fiber and microclay on the performance of soy based polyurethane foams. J Polym Environ2013; 21: 30–38.
91.
YehS-KLiuY-CWuW-Z, et al.Thermoplastic polyurethane/clay nanocomposite foam made by batch foaming. J Cell Plast2013; 49: 119–130.
92.
KercheEFDelucisR de APetzholdCL, et al.Rigid bio-based wood/polyurethane foam composites expanded under confinement. J Cell Plast2020; 1–12.
93.
ZhangZLiDXuM, et al.Synthesis of a novel phosphorus and nitrogen-containing flame retardant and its application in rigid polyurethane foam with expandable graphite. Polym Degrad Stab2020; 173: 109077.
94.
SinghISamalSKMohantyS, et al.Recent Advancement in plant-oil derived polyol based polyurethane foam for future perspective: a review. Eur J Lipid Sci Technol2019; 122: 13–14.
95.
ModestiMCostantiniFdal LagoE, et al.Valuable secondary raw material by chemical recycling of polyisocyanurate foams. Polym Degrad Stab2018; 156: 151–160.
96.
ModestiMLorenzettiASimioniF, et al.Expandable graphite as an intumescent flame retardant in polyisocyanurate-polyurethane foams. Polym Degrad Stab2002; 77: 195–202.
97.
LevchikSVWeilED. Thermal decomposition, combustion and fire-retardancy of polyurethanes—a review of the recent literature. Polym Int2004; 53: 1585–1610.
98.
DickCDominguez-RosadoEElingB, et al.The flammability of urethane-modified polyisocyanurates and its relationship to thermal degradation chemistry. Polymer (Guildf)2001; 42: 913–923.
99.
WangSDuXJiangY, et al.Synergetic enhancement of mechanical and fire-resistance performance of waterborne polyurethane by introducing two kinds of phosphorus–nitrogen flame retardant. J Colloid Interf Sci2019; 537: 197–205.
100.
KimSShinHRhimS, et al.Calibration of hyperelastic and hyperfoam constitutive models for an indentation event of rigid polyurethane foam. Compos Part B Eng2019; 163: 297–302.
101.
LevinBCPaaboMBraunEHarrisRHJr.Recent advances in flame retardancy of polymeric materials. In: LewinM (ed) Proceedings of conference on recent advances in flame retardancy of polymeric materials. Stamford, CT, USA, 1991: BCC Inc, Norwalk, CT, pp. 291–296.
102.
BottBFirthJGJonesTA. Evolution of toxic gases from heated plastics. Br Polym J1969; 1: 203–204.
103.
BorregueroAMSharmaPSpiteriC, et al.A novel click-chemistry approach to flame retardant polyurethanes. React Funct Polym2013; 73: 1207–1212.
104.
BianXCTangJHLiZM, et alDependence of flame -retardant properties on density of expandable graphite filled rigid polyurethane foam. J Appl Polym Sci2007; 104(5): 3347–3355.
105.
GodaESYoonKREl-sayedSH, et al.Halloysite nanotubes as smart flame retardant and economic reinforcing materials: a review. Thermochim Acta2018; 669: 173–184.
106.
DasariAYuZZCaiGP, et al.Recent developments in the fire retardancy of polymeric materials. Prog Polym Sci2013; 38: 1357–1387.
107.
PavlidouSPapaspyridesCD. A review on polymer-layered silicate nanocomposites. Prog Polym Sci2008; 33: 1119–1198.
108.
ChenHShenPChenM, et al.Highly efficient flame retardant polyurethane foam with alginate/clay aerogel coating. ACS Appl Mater Inter; 8: 32557–32564. DOI: 10.1021/acsami.6b11659
109.
LuSYHamertonI. Recent developments in the chemistry of halogen-free flame retardant polymers. Prog Polym Sci (Oxford)2002; 27: 1661–1712.
110.
SergeiV. Levchik. Introduction to flame retardancy and polymer flammability. In: MorganABWilkieCA (eds) Flame retardant polymer nanocomposites. Hoboken, NJ, USA: John Wiley & Sons, pp. 1–30.
111.
XuMMaKJiangD, et al.Hexa-[4-(glycidyloxycarbonyl) phenoxy]cyclotriphosphazene chain extender for preparing high-performance flame retardant polyamide 6 composites. Polymer (Guildf)2018; 146: 63–72.
112.
WangFTangQDuanX, et al.Effect of modified sepiolite nanofibers and hollow glass microspheres on performance of rigid polyurethane foams composite materials. Nanosci Nanotechnol Lett2014; 6: 524–531.
113.
SchartelBHullTR. Development of fire-retarded materials - Interpretation of cone calorimeter data. Fire Mater2007; 31: 327–354.
114.
GürsesA. Introduction to polymer–clay nanocomposites. 2016. Epub ahead of print 2016. DOI: 10.1201/b18716
115.
WongJFChanJXHassanAb, et al.Thermal and flammability properties of wollastonite-filled thermoplastic composites: a review. J Mater Sci2021; 56: 8911–8950.
116.
PatelPHullTRMoffattC. PEEK polymer flammability and the inadequacy of the UL-94 classification. Fire Mater2012; 36: 185–201.
117.
HuCFontaineGTranchardP, et al.In-situ investigation of temperature evolution of drippings via an optimized UL-94 instrumentation: Application to flame retarded polybutylene succinate. Polym Degrad Stab2018; 155: 145–152.
118.
WangXKalaliENWanJT, et al.Carbon-family materials for flame retardant polymeric materials. Prog Polym Sci2017; 69: 22–46.
119.
KiliarisPPapaspyridesCD. Polymer/layered silicate (clay) nanocomposites: an overview of flame retardancy. Prog Polym Sci2010; 35: 902–958.
120.
SuzanneMDelichatsiosMAZhangJP. Flame extinction properties of solids obtained from limiting oxygen index tests. Combust Flame2014; 161: 288–294.
121.
MorganABBundyM. Cone calorimeter analysis of UL-94 V-rated plastics. Fire Mater2007; 31: 257–283.
122.
HorrocksARTuneMCegielkaL. The burning behaviour of textiles and its assessment by oxygen-index methods. Text Prog1988; 18: 1–186.
123.
HeSHuYSongL, et al.Fire safety assessment of halogen-free flame retardant polypropylene based on cone calorimeter. J Fire Sci2007; 25: 109–118.
FenimoreCP. Candle-type test for flammability of polymers. In: LewinMAtlasSMPearceEM (eds) Flame-retardant polymeric materials. Boston, MA: Springer, 1975, pp. 259–267.
126.
ShrivastavaA.Plastic Properties and testing. 2018. Epub ahead of print 2018. DOI: 10.1016/b978-0-323-39500-7.00003-4
127.
NorouziMZareYKianyP. Nanoparticles as effective flame retardants for natural and synthetic textile polymers: application, mechanism, and optimization. Polym Rev2015; 55: 531–560.
128.
NelsonMI. A dynamical systems model of the limiting oxygen index test: II. Retardancy due to char formation and addition of inert fillers. Combust Theor Model2001; 5: 59–83.
129.
YangHFuQChengX, et al.Investigation of the flammability of different cables using pyrolysis combustion flow calorimeter. In: Procedia engineering2013. 62: Elsevier, pp. 778–785.
130.
XiaoFFontaineGBourbigotS. Recent developments in fire retardancy of polybutylene succinate. Polym Degrad Stab2021; 183: 109466.
YangCQHeQ. Textile heat release properties measured by microscale combustion calorimetry: experimental repeatability. Fire Mater2012; 36: 127–137.
133.
LinTSCogenJMLyonRE. Correlations between microscale combustion calorimetry and conventional flammability tests for flame retardant wire and cable compounds. In: 56th IWCS conference: proceedings of the international wire & cable symposium (IWCS) 2007, Lake Buena Vista, Florida, USA, 11–14 November, 2007, 176–185.
134.
MensahRAXuQAsante-OkyereS, et al.Correlation analysis of cone calorimetry and microscale combustion calorimetry experiments. J Therm Anal Calorim2019; 136: 589–599.
135.
ZhugeJChenXKSA, et al.Microscale combustion calorimeter-application and limitation. Fire Mater2016; 40: 987–998.
136.
XuZDuanLHouY, et al.The influence of carbon-encapsulated transition metal oxide microparticles on reducing toxic gases release and smoke suppression of rigid polyurethane foam composites. Compos Part A Appl Sci Manuf2020; 131: 105815.
137.
DuWJinYLaiS, et al.Multifunctional light-responsive graphene-based polyurethane composites with shape memory, self-healing, and flame retardancy properties. Compos Part A Appl Sci Manuf2020; 128: 105686.
138.
BeyerG. Nanocomposites: a new class of flame retardants for polymers. Plast Addit Compd2002; 4: 22–28.
DarderMMatosCRSArandaP, et al.Bionanocomposite foams based on the assembly of starch and alginate with sepiolite fibrous clay. Carbohydr Polym2017; 157: 1933–1939.
141.
GeorgeJIshidaH. A review on the very high nanofiller-content nanocomposites: their preparation methods and properties with high aspect ratio fillers. Prog Polym Sci2018; 86: 1–39.
142.
BitinisNHernandezMVerdejoR, et al.Recent advances in clay/polymer nanocomposites. Adv Mater2011; 23: 5229–5236.
143.
ConradiM. Nanosilica-reinforced polymer composites. Mater Tehnol2013; 47: 285–293.
144.
VahabiHSaebMRFormelaK, et al.Flame retardant epoxy/halloysite nanotubes nanocomposite coatings: exploring low-concentration threshold for flammability compared to expandable graphite as superior fire retardant. Prog Org Coat2018; 119: 8–14.
145.
DuMGuoBJiaD. Newly emerging applications of halloysite nanotubes: a review. Polym Int2010; 59: 574–582.
146.
AlongiJHanZBourbigotS. Progress in polymer science intumescence: tradition versus novelty. A comprehensive review. Prog Polym Sci2015; 51: 28–73.
147.
OlivatoJBMariniJYamashitaF, et al.Sepiolite as a promising nanoclay for nano-biocomposites based on starch and biodegradable polyester. Mater Sci Eng C2017; 70: 296–302.
148.
LiuMPuMMaH. Preparation, structure and thermal properties of polylactide/sepiolite nanocomposites with and without organic modifiers. Compos Sci Technol2012; 72: 1508–1514.
149.
WilliamsBLDingHHouZ, et al.Highly efficient polyvinyl alcohol/montmorillonite flame retardant nanocoating for corrugated cardboard. Adv Compos Hybrid Mater2021; 4: 662–669.
150.
YuanBFanAYangM, et al.The effects of graphene on the flammability and fire behavior of intumescent flame retardant polypropylene composites at different flame scenarios. Polym Degrad Stab2017; 143: 42–56.
151.
GrandeRPessanLA. Effects of nanoclay addition on phase morphology and stability of polycarbonate/styrene-acrylonitrile blends. Appl Clay Sci2017; 140: 112–118.
152.
PereiraCMCMartinsMSS. Flame retardancy of fiber-reinforced polymer composites based on nanoclays and carbon nanotubes. In: Polymer Green Flame Retardants2014, pp. 551–595: Elsevier. DOI: 10.1016/B978-0-444-53808-6.00017-2
153.
TangGDengDChenJ, et al.The influence of organo-modified sepiolite on the flame-retardant and thermal properties of intumescent flame-retardant polylactide composites. J Therm Anal Calorim2017; 130: 763–772.
154.
PunethaVDRanaSYooHJ, et al.Functionalization of carbon nanomaterials for advanced polymer nanocomposites: a comparison study between CNT and graphene. Prog Polym Sci2017; 67: 1–47.
155.
DemczykBGWangYMCumingsJ, et al.Direct mechanical measurement of the tensile strength and elastic modulus of multiwalled carbon nanotubes. Mater Sci Eng A2002; 334: 173–178.
156.
PanDLuoSFengY, et al.Highly thermally conductive 3D BN/MWCNTs/C spatial network composites with improved electrically insulating and flame retardancy prepared by biological template assisted method. Compos Part B Eng2021; 222: 109039.
157.
PintoVCRamosTAlvesASF, et al.Dispersion and failure analysis of PLA, PLA/GNP and PLA/CNT-COOH biodegradable nanocomposites by SEM and DIC inspection. Eng Fail Anal2017; 71: 63–71.
158.
AnbusagarNRRPalanikumarKPonshanmugakumarA. Preparation and properties of nanopolymer advanced composites: a review. In: JawaidMKM (ed) Polymer-based nanocomposites for energy and environmental applications: a volume in woodhead publishing series in composites science and engineering. Australia: Elsevier, pp. 28–73.
159.
AlisAMajidRAMohamadZ. Morphologies and thermal properties of palm-oil based rigid polyurethane/halloysite nanocomposite foams. Chem Eng Trans2019; 72: 415–420.
160.
Espadas-EscalanteJAvilésFGonzalez-ChiP, et al.Thermal conductivity and flammability of multiwall carbon nanotube/polyurethane foam composites. J Cell Plast2017; 53: 215–230.
161.
KashiwagiTDuFDouglasJF, et al.Nanoparticle networks reduce the flammability of polymer nanocomposites. Nat Mater2005; 4: 928–933.
162.
YangBChenYZhangM, et al.Synergistic and compatibilizing effect of octavinyl polyhedral oligomeric silsesquioxane nanoparticles in polypropylene/intumescent flame retardant composite system. Compos Part A Appl Sci Manuf2019; 123: 46–58.
163.
SalasinskaKBoruckaMLeszczyńskaM, et al.Analysis of flammability and smoke emission of rigid polyurethane foams modified with nanoparticles and halogen-free fire retardants. J Therm Anal Calorim2017; 130: 131–141.
164.
de JuanSZhangJAcuñaP, et al.An efficient approach to improving fire retardancy and smoke suppression for intumescent flame-retardant polypropylene composites via incorporating organo-modified sepiolite. Fire Mater2019; 43: 961–970.
165.
CzłonkaSKairytėAMiedzińskaK, et al.Mechanically strong polyurethane composites reinforced with montmorillonite-modified sage filler (Salvia officinalis l.). Int J Mol Sci; 22: 3744. DOI: 10.3390/ijms22073744
166.
LiYZhangXChenX, et al.Zeolite Imidazolate Framework Membranes on Polymeric Substrates Modified with Poly(vinyl alcohol) and Alginate Composite Hydrogels. ACS Appl Mater Inter2019; 11: 12605–12612.
167.
ZanettiMCostaL. Preparation and combustion behaviour of polymer/layered silicate nanocomposites based upon PE and EVA. Polymer (Guildf)2004; 45: 4367–4373.
168.
ZhengXWangGXuW. Roles of organically-modified montmorillonite and phosphorous flame retardant during the combustion of rigid polyurethane foam. Polym Degrad Stab2014; 101: 32–39.
169.
CulebrasMCollinsGABeaucampA, et al.Lignin/si hybrid carbon nanofibers towards highly efficient sustainable li-ion anode materials. Eng Sci2022; 17: 195–203.
170.
XuGShiZZhaoY, et al.Structural characterization of lignin and its carbohydrate complexes isolated from bamboo (Dendrocalamus sinicus). Int J Biol Macromol2019; 126: 376–384.
171.
MaYLvLGuoY, et al.Porous lignin based poly (acrylic acid)/organo-montmorillonite nanocomposites: swelling behaviors and rapid removal of Pb (II) ions. Polymer (Guildf)2017; 128: 12–23.
172.
MuLDongYLiL, et al.achieving high value utilization of bio-oil from lignin targeting for advanced lubrication. ES Mater Manuf2021; 11: 72–80.
173.
WangYHuYJHaoX, et al.Hydrothermal synthesis and applications of advanced carbonaceous materials from biomass: a review. Adv Compos Hybrid Mater2020; 3: 267–284.
174.
HiroseS. Novel epoxy resins with unsaturated ester chains derived from sodium lignosulfonate. Macromol Symp2015; 353: 31–38.
175.
ThakurVKThakurMKRaghavanP, et al.Progress in green polymer composites from lignin for multifunctional applications: a review. ACS Sustain Chem Eng2014; 2: 1072–1092.
176.
FerryLDorezGTaguetA, et al.Chemical modification of lignin by phosphorus molecules to improve the fire behavior of polybutylene succinate. Polym Degrad Stab2015; 113: 135–143.
177.
De ChiricoAArmaniniMChiniP, et al.Flame retardants for polypropylene based on lignin. Polym Degrad Stab2003; 79: 139–145.
178.
CanettiMBertiniFDe ChiricoA, et al.Thermal degradation behaviour of isotactic polypropylene blended with lignin. Polym Degrad Stab2006; 91: 494–498.
179.
LuWLiQZhangY, et al.Lignosulfonate/APP IFR and its flame retardancy in lignosulfonate-based rigid polyurethane foams. J Wood Sci2018; 64: 287–293.
180.
ZhuHPengZChenY, et al.Preparation and characterization of flame retardant polyurethane foams containing phosphorus-nitrogen-functionalized lignin. RSC Adv2014; 4: 55271–55279.
181.
WilkieCA. Fire retardancy of polymers: the use of intumescence. United Kingdom: The Royal Society of Chemistry, 2009. DOI: 10.1016/s1369-7021(09)70137-3
182.
BhoyateSIonescuMKaholPK, et al.Sustainable flame-retardant polyurethanes using renewable resources. Ind Crops Prod2018; 123: 480–488.
183.
HuangGChenSSongP, et al.Combination effects of graphene and layered double hydroxides on intumescent flame-retardant poly(methyl methacrylate) nanocomposites. Appl Clay Sci2014; 88–89: 78–85.
184.
LiangCDuYWangY, et al.Intumescent fire-retardant coatings for ancient wooden architectures with ideal electromagnetic interference shielding. Adv Compos Hybrid Mater2021; 4: 979–988.
185.
XingYLiYQLinZ, et al.Synthesis and characterization of bio-based intumescent flame retardant and its application in polyurethane. Fire Mater2020; 44: 814–824.
186.
HuSSongLPanH, et al.Effect of a novel chitosan-based flame retardant on thermal and flammability properties of polyvinyl alcohol. J Therm Anal Calorim2013; 112: 859–864.
187.
LevchikS VLevchikGFBalabanovichAI, et al.Mechanistic study of combustion performance and thermal decomposition behaviour of nylon 6 with added halogen-free fire retardants. Polym Degrad Stab1996; 54: 217–222.
188.
KangXLuZFengW, et al.A novel phosphorous and silicon-containing benzoxazine: highly efficient multifunctional flame-retardant synergist for polyoxymethylene. Adv Compos Hybrid Mater2021; 4: 127–137.
189.
LewinM.Synergistic and catalytic effects in flame retardancy of polymeric materials - an overview. J Fire Sci1999; 17: 3–19.
190.
LiJMoXLiY, et al.Effect of zeolites on morphology and properties of water-blown semi-rigid ammonium polyphosphate intumescent flame-retarding polyurethane foam. J Polym Res2017; 24: 154.
191.
LiQWangJChenL, et al.Ammonium polyphosphate modified with β-cyclodextrin crosslinking rigid polyurethane foam: enhancing thermal stability and suppressing flame spread. Polym Degrad Stab2019; 161: 166–174.
192.
StarkNMWhiteRHMuellerSA, et al.Evaluation of various fire retardants for use in wood flour-polyethylene composites. Polym Degrad Stab2010; 95: 1903–1910.
193.
ZhaoWKumar KunduCLiZ, et al.Flame retardant treatments for polypropylene: strategies and recent advances. Compos Part A Appl Sci Manuf2021; 145: 106382.
194.
WangWZhangWZhangS, et al.Preparation and characterization of microencapsulated ammonium polyphosphate with UMF and its application in WPCs. Constr Build Mater2014; 65: 151–158.
195.
JinXCuiSSunS, et al.The preparation of a bio-polyelectrolytes based core-shell structure and its application in flame retardant polylactic acid composites. Compos Part A Appl Sci Manuf2019; 124: 105485.
196.
YangYChenWLiuM, et al.Flame retarded rigid polyurethane foam composites based on gel-silica microencapsulated ammonium polyphosphate. J Sol-gel Sci Technol2021; 98: 212–223.
197.
TangGJiangHYangY, et al.Preparation of melamine–formaldehyde resin-microencapsulated ammonium polyphosphate and its application in flame retardant rigid polyurethane foam composites. J Polym Res; 27: 375. DOI: 10.1007/s10965-020-02343-7
198.
ChenYLiLWangW, et al.Preparation and characterization of surface-modified ammonium polyphosphate and its effect on the flame retardancy of rigid polyurethane foam. J Appl Polym Sci2017; 134: 45369.
199.
RaoWHHuZYXuHX, et al.Flame-retardant flexible polyurethane foams with highly efficient melamine salt. Ind Eng Chem Res2017; 56: 7112–7119.
200.
CuiMLiJQinD, et al.Intumescent flame retardant behavior of triazine group and ammonium polyphosphate in waterborne polyurethane. Polym Degrad Stab2021; 183: 109439.
201.
LuoFWuKGuoH, et al.Effect of cellulose whisker and ammonium polyphosphate on thermal properties and flammability performance of rigid polyurethane foam. J Therm Anal Calorim2015; 122: 717–723.
202.
ZhuHXuS. Preparation of flame-retardant rigid polyurethane foams by combining modified melamine-formaldehyde resin and phosphorus flame retardants. ACS Omega2020; 5: 9658–9667.
203.
XuWWangGZhengX. Research on highly flame-retardant rigid PU foams by combination of nanostructured additives and phosphorus flame retardants. Polym Degrad Stab2015; 111: 142–150.
204.
HolleMJMisakHEMalikRA, et al.Structural analysis and wear behavior of different graphite-based brushes for aircraft starter generator application. Adv Compos Hybrid Mater2021; 4: 162–172.
205.
HeYDuanRZhangQ, et al.Reinforce the mechanical toughness, heat resistance, and friction and wear resistance of phenolic resin via constructing self-assembled hybrid particles of graphite oxide and zirconia as nano-fillers. Adv Compos Hybrid Mater2021; 4: 317–323.
206.
HuXWuHLuX, et al.Improving thermal conductivity of ethylene propylene diene monomer/paraffin/expanded graphite shape-stabilized phase change materials with great thermal management potential via green steam explosion. Adv Compos Hybrid Mater2021; 4: 478–491.
207.
XieYYangYLiuY, et al.Paraffin/polyethylene/graphite composite phase change materials with enhanced thermal conductivity and leakage-proof. Adv Compos Hybrid Mater2021; 4: 543–551.
208.
ChengZLiaoDHuX, et al.Synergistic fire retardant effect between expandable graphite and ferrocene-based non-phosphorus polymer on polypropylene. Polym Degrad Stab2020; 178: 109201.
209.
YeLMengXYJiX, et al.Synthesis and characterization of expandable graphite-poly(methyl methacrylate) composite particles and their application to flame retardation of rigid polyurethane foams. Polym Degrad Stab2009; 94: 971–979.
210.
ChenYLuoYGuoX, et al.The synergistic effect of ionic liquid-modified expandable graphite and intumescent flame-retardant on flame-retardant rigid polyurethane foams. Materials (Basel)2020; 13: 3095.
211.
ZhangLZhangMZhouY, et al.The study of mechanical behavior and flame retardancy of castor oil phosphate-based rigid polyurethane foam composites containing expanded graphite and triethyl phosphate. Polym Degrad Stab2013; 98: 2784–2794.
ChenXYHuangZHXiXQ, et al.Synergistic effect of carbon and phosphorus flame retardants in rigid polyurethane foams. Fire Mater2018; 42: 447–453.
214.
ZhangX-GGeL-LZhangW-Q, et al.Expandable graphite-methyl methacrylate-acrylic acid copolymer composite particles as a flame retardant of rigid polyurethane foam. J Appl Polym Sci2011; 122: 932–941.
215.
GharehbaghiABashirzadehRAhmadiZ. Polyurethane flexible foam fire resisting by melamine and expandable graphite: Industrial approach. J Cell Plast2011; 47: 549–565.
216.
LingYXian-YanMXing-MaoL, et al.Flame-retardant and mechanical properties of high-density rigid polyurethane foams filled with decabrominated dipheny ethane and expandable graphite. J Appl Polym Sci2009; 111: 2372–2380.
217.
ZhangXLDuanHJYanDX, et al.A facile strategy to fabricate microencapsulated expandable graphite as a flame-retardant for rigid polyurethane foams. J Appl Polym Sci2015; 132: 1–9.
218.
WangYWangFDongQ, et al.Expandable graphite encapsulated by magnesium hydroxide nanosheets as an intumescent flame retardant for rigid polyurethane foams. J Appl Polym Sci2018; 135: 46749.
219.
LewinM.Synergism and Catalysis in Flame Retardancy of Polymers †. Polym Adv Technol2001; 222: 215–222.
220.
CaminoGGrassieNMcNeillIC. Influence of the fire retardant, ammonium polyphosphate, on the thermal degradation of poly(methyl methacrylate). J Polym Sci Polym Chem Ed1978; 16: 95–106.
221.
SinghHJainAK. Ignition, combustion, toxicity, and fire retardancy of polyurethane foams: a comprehensive review. J Appl Polym Sci2009; 111: 1115–1143.
222.
LiuMFengZZhaoR, et al.Enhancement of fire performance for rigid polyurethane foam composites by incorporation of aluminum hypophosphite and expanded graphite. Polym Bull2022; 79: 1–22.
223.
AcuñaPLinXCalvoMS, et al.Synergistic effect of expandable graphite and phenylphosphonic-aniline salt on flame retardancy of rigid polyurethane foam. Polym Degrad Stab2020; 179: 109274.
224.
StrąkowskaACzłonkaSKoncaP, et al.New flame retardant systems based on expanded graphite for rigid polyurethane foams. Appl Sci2020; 10: 5817.
225.
LiuLWangZZhuM. Flame retardant, mechanical and thermal insulating properties of rigid polyurethane foam modified by nano zirconium amino-tris-(methylenephosphonate) and expandable graphite. Polym Degrad Stab2019; 170: 108997.
226.
LiLChenYQianL, et al.Addition flame-retardant effect of nonreactive phosphonate and expandable graphite in rigid polyurethane foams. J Appl Polym Sci2018; 135: 45960.
227.
WangSQianLXinF. The synergistic flame-retardant behaviors of pentaerythritol phosphate and expandable graphite in rigid polyurethane foams. Polym Compos2018; 39: 329–336.
228.
YildirimIZPrezziM. Chemical, mineralogical, and morphological properties of steel slag. Adv Civ Eng2011; 2011: 1–13.
229.
ZhangT-SLiuF-TLiuS-Q, et al.Factors influencing the properties of a steel slag composite cement. Adv Cem Res2008; 20: 145–150.
230.
LiB. A study of the thermal decomposition and smoke suppression of poly(vinyl chloride) treated with metal oxides using a cone calorimeter at a high incident heat flux. Polym Degrad Stab2002; 78: 349–356.
231.
TangGLiuXYangY, et al.Phosphorus-containing silane modified steel slag waste to reduce fire hazards of rigid polyurethane foams. Adv Powder Technol2020; 31: 1420–1430.
232.
TangGLiuXZhouL, et al.Steel slag waste combined with melamine pyrophosphate as a flame retardant for rigid polyurethane foams. Adv Powder Technol2020; 31: 279–286.
LuWJinZ. Synthesis of phosphorus/nitrogen containing intumescent flame retardants from p-hydroxybenzaldehyde, vanillin and syringaldehyde for rigid polyurethane foams. Polym Degrad Stab2022; 195: 109768.
235.
QianXLiuQZhangL, et al.Synthesis of reactive DOPO-based flame retardant and its application in rigid polyisocyanurate-polyurethane foam. Polym Degrad Stab2022; 197: 109852.
236.
WangJXuBWangX, et al.A phosphorous-based bi-functional flame retardant for rigid polyurethane foam. Polym Degrad Stab2021; 186: 109516.
