首次以聚磷酸铵(APP)为酸源和主阻燃剂,以高氮含量的三聚氰胺氰尿酸盐(MCA)为气源,以大分子型三嗪成炭剂(CFA)为炭源,组成APP-MCA-CFA三元复配阻燃剂体系。将其用于环氧树脂体系的阻燃改性,通过极限氧指数(LOI)、垂直燃烧等级、锥形量热、扫描电镜(SEM)、热失重分析(TG)和动态力学分析(DMA)等实验分析了它们之间的协同效应。结果表明:与单独使用APP阻燃剂相比,三元复配阻燃剂体系(20% APP-5% MCA-5% CFA,均为质量分数)表现出显著的协同阻燃效应,LOI值提升至62.0%,热释放速率峰值(PHRR)降低至401kW/m2,总热释放量(THR)下降至37.3MW/m2。成炭分析结果表明,APP-MCA-CFA三元复配阻燃剂体系的引入使环氧树脂在高温下形成孔洞直径约5μm的形貌均一且规整的微米级膨胀炭层。DMA实验表明MCA和CFA可以通过粒子表面的胺基参与环氧固化反应,提高环氧固化交联密度,在一定程度抵消APP阻燃剂粉体加入导致的环氧机械性能下降。APP-MCA-CFA三元复配阻燃体系可用于环氧树脂基玻璃纤维复合材料的阻燃改性,垂直燃烧等级提升至UL-94 V0级,LOI值提升至66.3%。该研究为开发综合性能优异的阻燃环氧树脂基复合体系提供了一种简单易行的途径。
The ternary APP-MCA-CFA flame retardant system was composed of ammonium polyphosphate (APP) as the acid source and the main flame retardant,melamine cyanurate (MCA) with the high nitrogen content as the gas source,and triazine-based macromolecular carbon-forming agent (CFA) as the carbon source for the first time.We used this ternary APP-MCA-CFA system in the flame retardant modification of epoxy resin and then studied the synergistic flame retardancy effect of this ternary APP-MCA-CFA system via limiting oxygen index (LOI) test,vertical combustion grade,conical calorimetry tests,scanning electron microscopy (SEM) and thermogravimetric analysis (TG).The results displayed that this ternary APP-MCA-CFA system (20wt% APP-5wt% MCA-5wt% CFA) exhibited apparent synergistic flame retardancy effect compared with APP alone.The LOI increased to 62.09%,the peak of heat release rate (PHRR) decreased to 401 kW/m2,and the total heat release rate (THR) decreased to 37.3MW/m2.According to the analyses of char residues,the introduction of ternary APP-MCA-CFA system resulted in the formation of a uniform and regular micron-scale expanded char layer with pore diameters of approximately 5μm at high temperatures.DMA experiments showed that MCA and CFA could participate in epoxy curing reaction through the amine groups on the particle surface,which improved the cross-linking density of epoxy curing and offset the reduction of mechanical properties caused by the addition of APP flame retardant powder.Moreover,we incorporated this ternary APP-MCA-CFA system for flame retardant modification of epoxy resin-based glass fiber reinforced composite (GFRC),achieving a vertical burning grade of UL-94 V0 and a LOI value of 66.3%.This study provided an effective strategy to develop epoxy resin-based composite systems with excellent comprehensive performance.
[1] Rocha I B C M,Raijmaekers S,Nijssen R P L,et al.Hygrothermal ageing behaviour of a glass/epoxy composite used in wind turbine blades[J].Composite Structures,2017,174:110-122.
[2] Jin F L,Li X,Park S J.Synthesis and application of epoxy resins:a review[J].Journal of Industrial and Engineering Chemistry,2015,29:1-11.
[3] Auvergne R,Caillol S,David G,et al.Biobased thermosetting epoxy:present and future[J].Chemical Reviews,2014,114(2):1082-1115.
[4] Zhou K,Tang G,Gao R,et al.In situ growth of 0D silica nanospheres on 2D molybdenum disulfide nanosheets:towards reducing fire hazards of epoxy resin[J].Journal of Hazardous Materials,2018,344:1078-1089.
[5] Kong Q,Sun Y,Zhang C,et al.Ultrathin iron phenyl phosphonate nanosheets with appropriate thermal stability for improving fire safety in epoxy[J].Composites Science and Technology,2019,182:107748.
[6] Jiang S D,Tang G,Chen J,et al.Biobased polyelectrolyte multilayer-coated hollow mesoporous silica as a green flame retardant for epoxy resin[J].Journal of Hazardous Materials,2018,342:689-697.
[7] Gong K,Zhou K,Yu B.Superior thermal and fire safety performances of epoxy-based composites with phosphorus-doped cerium oxide nanosheets[J].Applied Surface Science,2020,504:144314-144324.
[8] Rahman F,Langford K H,Scrimshaw M D,et al.Polybrominated diphenyl ether (PBDE) flame retardants[J].Science of the Total Environment,2001,275(1-3):1-17.
[9] De Wit C A.An overview of brominated flame retardants in the environment[J].Chemosphere,2002,46(5):583-624.
[10] Söderström G,Marklund S.PBCDD and PBCDF from incineration of waste-containing brominated flame retardants[J].Environmental Science & Technology,2002,36(9):1959-1964.
[11] Gu L,Ge Z,Huang M,et al.Halogen-free flame-retardant waterborne polyurethane with a novel cyclic structure of phosphorus-nitrogen synergistic flame retardant[J].Journal of Applied Polymer Science,2015,132(3):41288-41296.
[12] Perret B,Schartel B,Stöß K,et al.A new halogen-free flame retardant based on 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide for epoxy resins and their carbon fiber composites for the automotive and aviation industries[J].Macromolecular Materials and Engineering,2011,296(1):14-30.
[13] Mauerer O.New reactive,halogen-free flame retardant system for epoxy resins[J].Polymer Degradation and Stability,2005,88(1):70-73.
[14] Zhang W,He X,Song T,et al.The influence of the phosphorus-based flame retardant on the flame retardancy of the epoxy resins[J].Polymer Degradation and Stability,2014,109:209-217.
[15] Movahedifar E,Vahabi H,Saeb M R,et al.Flame retardant epoxy composites on the road of innovation:an analysis with flame retardancy index for future development[J].Molecules,2019,24(21):3964-4010.
[16] Liu Q,Wang D,Li Z,et al.Recent developments in the flame-retardant system of epoxy resin[J].Materials,2020,13(9):2145-2183.
[17] Feng C M,Zhang Y,Lang D,et al.Flame retardant mechanism of a novel intumescent flame retardant polypropylene[J].Procedia Engineering,2013,52:97-104.
[18] Brehme S,Schartel B,Goebbels J,et al.Phosphorus polyester versus aluminium phosphinate in poly (butylene terephthalate)(PBT):flame retardancy performance and mechanisms[J].Polymer Degradation and Stability,2011,96(5):875-884.
[19] Rajaei M,Kim N K,Bickerton S,et al.A comparative study on effects of natural and synthesised nano-clays on the fire and mechanical properties of epoxy composites[J].Composites Part B:Engineering,2019,165:65-74.
[20] Rajaei M,Wang D Y,Bhattacharyya D.Combined effects of ammonium polyphosphate and talc on the fire and mechanical properties of epoxy/glass fabric composites[J].Composites Part B:Engineering,2017,113:381-390.
[21] Matykiewicz D,Przybyszewski B,Stanik R,et al.Modification of glass reinforced epoxy composites by ammonium polyphosphate (APP) and melamine polyphosphate (PNA) during the resin powder molding process[J].Composites Part B:Engineering,2017,108:224-231.
[22] Zhang W,Chen Z,Yu Y,et al.Synthesis of phosphorus and silicon co-doped graphitic carbon nitride and its combination with ammonium polyphosphate to enhance the flame retardancy of epoxy resin[J].Journal of Applied Polymer Science,2022,139(6):51614-51626.
[23] Wang W,Liu Y,Wen H,et al.Synthesis of a hyperbranched polyamide charring agent and its flame-retarding and toughening behavior in epoxy resin[J].Polymer Degradation and Stability,2021,184:109479-109489.
[24] Li X L,Zhang F H,Jian R K,et al.Influence of eco-friendly calcium gluconate on the intumescent flame-retardant epoxy resin:flame retardancy,smoke suppression and mechanical properties[J].Composites Part B:Engineering,2019,176:107200-107208.
[25] Shi Y,Liu C,Duan Z,et al.Interface engineering of MXene towards super-tough and strong polymer nanocomposites with high ductility and excellent fire safety[J].Chemical Engineering Journal,2020,399:125829-125842.
[26] Liu L,Zhang Y,Li C,et al.Facile preparation PCL/modified nano ZnO organic-inorganic composite and its application in antibacterial materials[J].Journal of Polymer Research,2020,27(3):1-11.
[27] Chen W,Liu P,Cheng Y,et al.Flame retardancy mechanisms of melamine cyanurate in combination with aluminum diethylphosphinate in epoxy resin[J].Journal of Applied Polymer Science,2019,136(12):47223-47233.
[28] Hu X P,Li Y L,Wang Y Z.Synergistic effect of the charring agent on the thermal and flame retardant properties of polyethylene[J].Macromolecular Materials and Engineering,2004,289(2):208-212.
[29] Yang K,Xu M J,Li B.Synthesis of N-ethyl triazine-piperazine copolymer and flame retardancy and water resistance of intumescent flame retardant polypropylene[J].Polymer Degradation and Stability,2013,98(7):1397-1406.
[30] Wen P,Wang X,Xing W,et al.Synthesis of a novel triazine-based hyperbranched char foaming agent and the study of its enhancement on flame retardancy and thermal stability of polypropylene[J].Industrial & Engineering Chemistry Research,2013,52(48):17015-17022.
[31] Cheng K C,Kuo T H.Flame retardant and mechanical properties of epoxy composites with ammonium polyphosphate and hyperbranched silicon-containing polymers[J].Journal of Applied Polymer Science,2020,137(28):48857-48863.
[32] Tan Y,Shao Z B,Yu L X,et al.Piperazine-modified ammonium polyphosphate as monocomponent flame-retardant hardener for epoxy resin:flame retardance,curing behavior and mechanical property[J].Polymer Chemistry,2016,7(17):3003-3012.
[33] Nazare S,Kandola B,Horrocks A R.Use of cone calorimetry to quantify the burning hazard of apparel fabrics[J].Fire and Materials,2002,26(4):191-199.
[34] Koo J H,Venumbaka S,Cassidy P E,et al.Flammability studies of thermally resistant polymers using cone calorimetry[J].Fire and Materials,2000,24(5):209-218.
[35] Morice L,Bourbigot S,Leroy J M.Heat transfer study of polypropylene-based intumescent systems during combustion[J].Journal of Fire Sciences,1997,15(5):358-374.
[36] Kiliaris P,Papaspyrides C D,Pfaendner R.Polyamide 6 filled with melamine cyanurate and layered silicates:evaluation of flame retardancy and physical properties[J].Macromolecular Materials and Engineering,2008,293(9):740-751.
[37] Casu A,Camino G,De Giorgi M,et al.Fire-retardant mechanistic aspects of melamine cyanurate in polyamide copolymer[J].Polymer Degradation and Stability,1997,58(3):297-302.
[38] Wan M,Shen J,Sun C,et al.Ionic liquid modified graphene oxide for enhanced flame retardancy and mechanical properties of epoxy resin[J].Journal of Applied Polymer Science,2021,138:50757-50769.
[39] Bourbigot S,Le Bras M,Duquesne S,et al.Recent advances for intumescent polymers[J].Macromolecular Materials and Engineering,2004,289(6):499-511.
[40] Lin J,Wang K,Li J,et al.Growing metal-organic framework nanoparticles on short carbon fibers to improve flame retardancy,smoke suppression and mechanical properties of the flame retardant epoxy composites[J].Journal of Materials Science,2021,56(36):19899-19914.
[41] Kuzak S G,Shanmugam A.Dynamic mechanical analysis of fiber-reinforced phenolics[J].Journal of Applied Polymer Science,1999,73(5):649-658.
[42] Teh P L,Jaafar M,Akil H M,et al.Thermal and mechanical properties of particulate fillers filled epoxy composites for electronic packaging application[J].Polymers for Advanced Technologies,2008,19(4):308-315.
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