Flame-retardant behavior and mechanism of a DOPO-based phosphorus–nitrogen flame retardant in epoxy resin

2018 ◽  
Vol 31 (8) ◽  
pp. 885-892 ◽  
Author(s):  
Yanan Yan ◽  
Bing Liang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Phosphorus Content ◽  
Ionization Mass ◽  
Limiting Oxygen Index ◽  
Electrospray Ionization Mass Spectroscopy ◽  
Ionization Mass Spectroscopy ◽  
The Matrix ◽  
Ul 94 ◽  
Flame Retardant Properties

A novel flame-retardant additive, 6,6′,6″-((1,3,5-triazine-2,4,6 triyl) tris (azanediyl)) tris (dibenzo[c,e][1,2]oxaphosphinine 6-oxide) (DOPO-M), was synthesized from melamine and 9,10-dihy-dro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO). The structure of DOPO-M was characterized by Fourier transform infrared (FTIR) spectroscopy, proton (1H) and phosphorous (31P) nuclear magnetic resonance (NMR) spectroscopies, and electrospray ionization mass spectroscopy (ESI-MS). DOPO-M was blended into epoxy resin (EP) to prepare flame-retardant EPs. The flame-retardant and thermal properties of EPs cured with triethylenetetramine (TETA) were investigated by thermogravimetric analysis (TGA), the UL-94 test, and the limiting oxygen index (LOI) test. The results revealed that the epoxy thermosets exhibited excellent flame retardancy and passed the V-0 rating of the UL-94 test with an LOI of 29.3% when the phosphorus content was 2.57 wt%. The scanning electron microscopy (SEM) results showed that DOPO-M in the EP/TETA system obviously accelerated the formation of a stronger, phosphorus-rich sealing char layer to improve the flame-retardant properties of the matrix during combustion.

Synthesis of a boron/nitrogen-containing compound based on triazine and boronic acid and its flame retardant effect on epoxy resin

2016 ◽  
Vol 29 (5) ◽  
pp. 513-523 ◽  
Author(s):  
Tie Zhang ◽  
Weishi Liu ◽  
Meixiao Wang ◽  
Ping Liu ◽  
Yonghong Pan ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Boronic Acid ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Triazine Ring ◽  
Limiting Oxygen Index ◽  
Ul 94 ◽  
Flame Retardant Properties ◽  
Boron Nitrogen

With the aim of developing a novel organic flame retardant, an organic boronic acid derivative containing a triazine ring (2,4,6-tris(4-boronic-2-thiophene)-1,3,5-triazine (3TT-3BA)) was synthesized. The thermal properties of 3TT-3BA and its corresponding intermediate products were investigated by thermogravimetric analysis. The results show that 3TT-3BA has a high char yield (56.9%). The flame retardant properties of epoxy resin (EP) with 3TT-3BA were investigated by cone calorimeter, limiting oxygen index (LOI) test, and vertical burning test (UL 94). The LOI of EP with 20% 3TT-3BA is 31.2% and the UL 94 V-0 rating is achieved for EP with 20% 3TT-3BA. The flame retardant mechanism of 3TT-3BA in EP was investigated using TGA–Fourier transform infrared spectroscopy and scanning electron microscopy.

scholarly journals Preparation and properties of flame-retardant epoxy resins containing reactive phosphorus flame retardant

2020 ◽  
Vol 15 ◽  
pp. 155892502090132
Author(s):  
Sang-Hoon Lee ◽  
Seung-Won Oh ◽  
Young-Hee Lee ◽  
Il-Jin Kim ◽  
Dong-Jin Lee ◽  
...  
Keyword(s):  
Impact Strength ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Epoxy Resins ◽  
Phosphorus Content ◽  
Phosphorus Compound ◽  
Phosphorus Compounds ◽  
Limiting Oxygen Index ◽  
The Impact

To prepare flame-retardant epoxy resin, phosphorus compound containing di-hydroxyl group (10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phospha phenanthrene-10-oxide, DOPO-HQ) was reacted with uncured epoxy resin (diglycidyl ether of bisphenol A, YD-128) and then cured using a curing agent (dicyandiamide, DICY). This study focused on the effect of phosphorus compound/phosphorus content on physical properties and flame retardancy of cured epoxy resin. The thermal decomposition temperature of the cured epoxy resins (samples: P0, P1.5, P2.0, and P2.5, the number represents the wt% of phosphorus) increased with increasing the content of phosphorus compound/phosphorus (0/0, 19.8/1.5, 27.8/2.0, and 36.8/2.5 wt%) based on epoxy resin. The impact strength of the cured epoxy resin increased significantly with increasing phosphorus compound content. As the phosphorus compound/phosphorus content increased from 0/0 to 36.8/2.5 wt%, the glass transition temperature (the peak temperature of loss modulus curve) increased from 135.2°C to 142.0°C. In addition, as the content of phosphorous compound increased, the storage modulus remained almost constant up to higher temperature. The limiting oxygen index value of cured epoxy resin increased from 21.1% to 30.0% with increasing phosphorus compound/phosphorus content from 0/0 to 36.8/2.5 wt%. The UL 94 V test result showed that no rating for phosphorus compounds less than 19.8 wt% and V-1 for 27.8 wt%. However, when the phosphorus compound was 36.8 wt%, the V-0 level indicating complete flame retardancy was obtained. In conclusion, the incorporation of phosphorus compounds into the epoxy chain resulted in improved properties such as impact strength and heat resistance, as well as a significant increase in flame retardancy.

scholarly journals Synthesis of K-Carrageenan Flame-Retardant Microspheres and Its Application for Waterborne Epoxy Resin with Functionalized Graphene

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1708 ◽  
Author(s):  
Wang ◽  
Teng ◽  
Yang ◽  
You ◽  
Zhang ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Oxygen Index ◽  
Functionalized Graphene ◽  
Limiting Oxygen Index ◽  
Gas Source ◽  
Waterborne Epoxy ◽  
Emulsion Polymerizations ◽  
Flame Retardant Properties ◽  
Waterborne Epoxy Resin

In this article, the intumescent flame-retardant microsphere (KC-IFR) was prepared by inverse emulsion polymerizations, with the use of k-carrageenan (KC) as carbon source, ammonium polyphosphate (APP) as acid source, and melamine (MEL) as gas source. Meanwhile, benzoic acid functionalized graphene (BFG) was synthetized as a synergist. A “four-source flame-retardant system” (KC-IFR/BFG) was constructed with KC-IFR and BFG. KC-IFR/BFG was blended with waterborne epoxy resin (EP) to prepare flame-retardant coatings. The effects of different ratios of KC-IFR and BFG on the flame-retardant properties of EP were investigated. The results showed that the limiting oxygen index (LOI) values increased from 19.7% for the waterborne epoxy resin to 28.7% for the EP1 with 20 wt% KC-IFR. The addition of BFG further improved the LOI values of the composites. The LOI value reached 29.8% for the EP5 sample with 18 wt% KC-IFR and 2 wt% BFG and meanwhile, UL-94 test reached the V-0 level. In addition, the peak heat release (pHRR) and smoke release rate (SPR) of EP5 decreased by 63.5% and 65.4% comparing with EP0, respectively. This indicated the good flame-retardant and smoke suppression property of EP composites coating.

scholarly journals Preparation of Intercalated Organic Montmorillonite DOPO-MMT by Melting Method and Its Effect on Flame Retardancy to Epoxy Resin

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3496
Author(s):  
Junming Geng ◽  
Jianyu Qin ◽  
Jiyu He
Keyword(s):  
Electron Microscopy ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Characterization Methods ◽  
Melting Method ◽  
Organic Montmorillonite ◽  
Ul 94 ◽  
Flame Retardant Properties

An intercalated organic montmorillonite DOPO-MMT was prepared through the melting method using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as a modifier. Epoxy resin (EP) composites were prepared with DOPO-MMT, DOPO, MMT, and the physical mixtures of DOPO+MMT as flame retardants. The microstructure of the flame retardants and EP samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The flame retardant properties, thermal stability, and residual char structure of the EPs were studied by the limited oxygen index (LOI) test, the UL-94 vertical burning test, thermogravimetric analysis (TGA), the differential scanning calorimeter (DSC) test, the cone calorimeter (CONE) test as well as other characterization methods. The results showed that the intercalated organic montmorillonite DOPO-MMT can be successfully prepared by the melting method and that the MMT is evenly dispersed in the EP/DOPO-MMT composite in the form of nanosheets. The EP/DOPO-MMT nanocomposites showed the optimal flame retardancy (LOI, UL-94, PHRR, etc.) among the EPs with DOPO, MMT, and the physical mixture of DOPO+MMT. The flame-retardant grade of the material reached V-0.

scholarly journals PREPARATION OF IRON- REDUCED GRAPHENE OXIDE/ EPOXY RESIN COMPOSITE AND ITS FLAME RETARDANCY AND THERMAL STABILITY

10.6036/10327 ◽  
2022 ◽  
Vol 97 (1) ◽  
pp. 98-103
Author(s):  
XIAN WANG ◽  
JINLONG ZHUO ◽  
TIANQING XING ◽  
Xingran Wang
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Iron Powder ◽  
Flame Retardancy ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Industrial Manufacture ◽  
Ul 94

In order to reduce flammability, smoke release and enhance thermal stability of epoxy resin (EP), iron powder is mixed with graphene oxide/ epoxy resin (GO/EP) composite by mechanical blending. The combustion performance of composite material is investigated through limiting oxygen index (LOI), Underwriters Laboratory (UL)-94 test, and cone calorimeter test (CCT). Thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR) and scanning electron microscope (SEM) are also used to explore the mechanism of flame retardancy and smoke suppression. Results show that, with the addition of 0.5% mass fraction of GO and the corresponding iron powder combination (EP3 sample), the LOI value can achieve 32.5% while reaching the UL-94 V0 rating. Compare with EP0, the peaks of heat release rate, smoke production rate, and smoke factor values of EP3 are decreased by 42%, 60%, and 50%, respectively. The char and TG-FTIR data of EP3 reveal that it has a more compact structure, good thermal stability, and produce fewer toxic gases and smoke. Reduction of GO could inhibit the degradation of EP, and iron catalyzes the formation of carbonaceous char on the surface. Thus, the thermal stability and flame retardancy of EP are improved significantly. This study provides a suitable way to prepare graphene/EP composites that contain iron catalyst and can be extended to the industrial manufacture of flame retardant polymer composites. Keywords: iron powder; epoxy resin; graphene oxide; flame retardant; thermal stability

Research on NPM Used in Flame Retardant Epoxy Potting

2012 ◽  
Vol 586 ◽  
pp. 172-176
Author(s):  
Hao Ran Zhou ◽  
Hao Cheng Yang ◽  
An Sun ◽  
Shuang Zhao
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Oxygen Index ◽  
Phosphorus Oxychloride ◽  
Gravimetric Analysis ◽  
Limiting Oxygen Index ◽  
Neopentyl Glycol ◽  
Melamine Salt ◽  
Flame Retardant Properties ◽  
Potting Compound

As the epoxy potting compound widely used, their flame retardant properties were concerned day by day.This paper neopentyl glycol phosphate melamine salt (NPM) was synthesised via phosphorus oxychloride as the acid source, neopentyl glycol as carbon source, melamine as gas source. The structure of NPM was characterized via infrared spectroscopic analysis (IR). Then the flame retardant properties of NPM/epoxy resin systerm were researched via the limiting oxygen index (LOI), vertical burning experiment, thermal gravimetric analysis (TGA) . The result shows that When the dosage of NPM is 27%, limiting oxygen index of epoxy resin have a extremum, is 32.4, char yield is 18.7% at 600°C. NPM can play a significant role in the improvement of the flame retardant properties of the epoxy.

Investigation of nickel ammonia phosphate with different morphologies as a new high-efficiency flame retardant for epoxy resin

2019 ◽  
Vol 32 (4) ◽  
pp. 359-370 ◽  
Author(s):  
Weiwei Zhang ◽  
Hongjuan Wu ◽  
Weihua Meng ◽  
Jiahe Li ◽  
Yumeng Cui ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Ammonium Phosphate ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
The Matrix

Nanowires, nanosheets, and microflowers of nickel ammonium phosphate (NiNH4PO4·H2O) were synthesized by a mixed solvothermal method and used to improve the flame retardancy of epoxy resin (EP). The solvent concentration and surfactant content were found to play a key role in nucleation and growth of NiNH4PO4·H2O. The structure of NiNH4PO4·H2O was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The flame retardancy, thermostability, mechanical properties, and flame retardancy mechanism of EP/NiNH4PO4·H2O composites were analyzed using the limiting oxygen index (LOI), cone calorimetry (Cone), mechanical property tests, thermogravimetric analysis, and thermogravimetric–Fourier transform infrared spectroscopy. The results indicated that NiNH4PO4·H2O has proper thermal stability and greatly improves the flame retardancy of EP. The nanosheets outperformed the other morphologies; the EP/5% NiNH4PO4·H2O nanosheets have an LOI of 35.2%, which exceeds that of pure EP (24.7%). Furthermore, Cone showed that these nanosheets have the lowest peak heat release rate and peak smoke production rate, which are 69.1% and 36.5% lower than those of pure EP, respectively. NiNH4PO4·H2O can promote the formation of a stable char layer and release nonflammable gases, thus protecting the matrix by preventing heat and oxygen transfer and reducing the concentration of combustible gas. NiNH4PO4·H2O is expected to serve as a new high-efficiency flame retardant for EP.

Poly(diallyldimethylammonium) and polyphosphate polyelectrolyte complex as flame retardant for char-forming epoxy resins

2020 ◽  
Vol 38 (4) ◽  
pp. 333-347
Author(s):  
Lichen Zhang ◽  
Deqi Yi ◽  
Jianwei Hao
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Polyelectrolyte Complex ◽  
Oxygen Index ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
Smoke Production ◽  
Ul 94

The flame retardant poly(diallyldimethylammonium) and polyphosphate polyelectrolyte complex and the curing agent m-Phenylenediamine were blended into diglycidyl ether of bisphenol A (DGEBA)-type epoxy resin to prepare flame-retardant epoxy resin thermosets. The effects of poly(diallyldimethylammonium) and polyphosphate on fire retardancy and thermal degradation behavior of epoxy resins (EP)/poly(diallyldimethylammonium) and polyphosphate composites were tested by Limiting Oxygen Index, UL-94, cone calorimeter tests, and thermogravimetric analysis and compared with pure EP. The results showed that the Limiting Oxygen Index value of EP/poly(diallyldimethylammonium) and polyphosphate composite could reach 31.9%, and UL-94 V-0 rating at 10 wt% poly(diallyldimethylammonium) and polyphosphate loading. Meanwhile the cone calorimetry peak heat release rate and total heat release were reduced up to 55.2% and 21.8%, respectively; smoke production rate and total smoke production were also declined significantly, compared with those of pure epoxy resins. Poly(diallyldimethylammonium) and polyphosphate played a very good flame-retardant effect on epoxy resins.

scholarly journals Polycarbonate/Sulfonamide Composites with Ultralow Contents of Halogen-Free Flame Retardant and Desirable Compatibility

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3656
Author(s):  
Hangfeng Yang ◽  
Hangbo Yue ◽  
Xi Zhao ◽  
Minzimo Song ◽  
Jianwei Guo ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Smoke Emission ◽  
Limiting Oxygen Index ◽  
Ul 94 ◽  
Flame Retardant Properties ◽  
Halogen Free ◽  
Sem Morphology ◽  
Limited Oxygen

A novel halogen-free flame retardant containing sulfonamide, 1,3,5,7-tetrakis (phenyl-4-sulfonamide) adamantane (FRSN) was synthesized and used for improving the flame retardancy of largely used polycarbonate (PC). The flame-retardant properties of the composites with incorporation of varied amounts of FRSN were analyzed by techniques including limited oxygen index, UL 94 vertical burning, and cone calorimeter tests. The new FR system with sulfur and nitrogen elements showed effective improvements in PC’s flame retardancy: the LOI value of the modified PC increased significantly, smoke emission suppressed, and UL 94 V-0 achieved. Typically, the composite with only 0.08 wt% of FRSN added (an ultralow content) can increase the limiting oxygen index (LOI) value to 33.7% and classified as UL 94 V-0 rating. Furthermore, the mechanical properties and SEM morphology indicated that the FRSN has very good compatibility with PC matrix, which, in turn, is beneficial to the property enhancement. Finally, the analysis of sample residues after burning tests showed that a high portion of char was formed, contributing to the PC burning protection. This synthesized flame retardant provides a new way of improving PC’s flame retardancy and its mechanical property.

Synthesis and Properties of Flame-Retardant Waterborne Emulsion Derived from O-Cresol Formaldehyde Epoxy Resin

2013 ◽  
Vol 652-654 ◽  
pp. 84-88
Author(s):  
Jian Xiong Wei ◽  
Gui Long Xu ◽  
Jian Hu ◽  
Jin Yang
Keyword(s):  
Acetic Acid ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Condensed Phase ◽  
Flame Retardancy ◽  
Phosphorus Content ◽  
Flame Retardant Property ◽  
Ul 94 ◽  
Waterborne Emulsion ◽  
Epoxy Emulsion

By modifying O-cresol Formaldehyde epoxy resin with DOPO and Diethanolamine, and then neutralized by acetic acid, phosphorous-containing epoxy emulsion with excellent flame retardancy can be obtained under strong agitation. Diethanolamine opening rate and neutralized degree to the formation of epoxy emulsion were optimized. The flame-retardant property of the cured phosphorous-containing epoxy resin was test by UL-94, LOI and TGA method. The result shows that when the opening rate of Diethanolamine is 25.0% and the neutralized degree is 95.0%, stable epoxy emulsion can be obtained. When phosphorus content of the epoxy resin was 3.0wt%, the LOI value of the resin can be reach to 39.2 and pass the UL-94 test，the 700°C char remaining is 30.0wt%. The result shows that the flame retardant mechanism of the phosphorous-containing epoxy resin is mainly through a condensed- phase mechanism.

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