A transparent and intumescent phosphaphenanthrene/phenylpyrazole-containing epoxy resin system and its flame retardancy

A novel intumescent flame retardant, PPMD, was designed from phosphaphenanthrene and nitrogen heterocycles through the two-step gut reactions of 1,4-phthalaldehyde and 3-methyl-1-phe-nylpyrazol-5-ylamine. After determination of its structure by nuclear magnetic resonance and Fourier-transform infrared analyses, PPMD was added to an epoxy resin (EP) to facilitate a curing process. Thus, EP/PPMD samples with excellent transparency and flame retardancy were acquired. For example, the EP sample satisfied the UL-94 V-0 standard and achieved a limiting oxygen index value of 30.5% because of the incorporation of 5 wt% PPMD. The cone calorimeter test of the EP/5% PPMD sample revealed that its total smoke production (TSP) and total heat release (THR) values of EP/5% PPMD was only 22.5% and 56.4% of the control group, respectively. Moreover, the average effective heat of combustion (av-EHC) value of EP/5% PPMD was reduced by 34.1%, indicating that PPMD possessed high flame-inhibition activity and smoke suppression efficiency. The flame-retardant mechanisms of PPMD were also investigated in gas phase by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and in condensed phase by XPS and IR.

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

DYNA INGENIERIA E INDUSTRIA ◽

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

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Novel flame retardancy effect of phenethyl-bridged DOPO derivative on epoxy resin

High Performance Polymers ◽

10.1177/0954008317716525 ◽

2017 ◽

Vol 30 (6) ◽

pp. 667-676 ◽

Cited By ~ 7

Author(s):

Wei Yan ◽

Jie Yu ◽

Mingqiu Zhang ◽

Lijuan Long ◽

Tao Wang ◽

...

Keyword(s):

Flame Retardant ◽

Visual Observation ◽

Gas Chromatography Mass Spectrometry ◽

Infrared Spectrometry ◽

Pyrolysis Gas ◽

Limiting Oxygen Index ◽

Cone Calorimeter Test ◽

Potential Applications ◽

Flame Retardant Properties ◽

Oxide Derivative

A series of flame-retardant epoxy resins (EPs) containing either phenethyl-bridged 9 or 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative (bisDOPO) were prepared. The flame-retardant properties of bisDOPO on EP composites were characterized by the limiting oxygen index (LOI), the UL-94 vertical burning, and the cone calorimeter test (CCT).The LOI of the EP/bisDOPO composites increased from 21.8% to 38.0%, and the hybrids with the 10 wt% bisDOPO obtained a V-0 rating in the UL94 vertical burning test. The char residue following the CCT showed intumescent structures with continuous and compact surfaces that can effectively suppress the spread of the flame and extinguish the fire. This was confirmed through both visual observation and scanning electron microscopy (SEM) measurements. The flame-retardant mechanism was studied by Fourier transform infrared spectroscope (FTIR), thermogravimetric analysis/infrared spectrometry, SEM/energy-dispersive X-ray, and pyrolysis-gas chromatography/mass spectrometry. Overall, bisDOPO was an effective flame retardant with potential applications within EP.

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An efficient flame retardant for epoxy resin: Preparation and pyrolytic behaviour

High Performance Polymers ◽

10.1177/0954008318815730 ◽

2018 ◽

Vol 31 (9-10) ◽

pp. 1009-1019 ◽

Cited By ~ 4

Author(s):

Baoping Yang ◽

Xiang Li ◽

Lurong Wang ◽

Yabin Zhang ◽

Jinfeng Cui ◽

...

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

High Efficiency ◽

Mass Spectrometry Analysis ◽

Gas Chromatography Mass Spectrometry ◽

Test Results ◽

Pyrolysis Gas ◽

Spectrometry Analysis ◽

Combined Test

Using 4,4-diaminodiphenyl methane as a curing agent, three kinds of monomers, 4,4′-dihydroxybenzophenone, diphenyl chlorophosphite and 1,4-phenylene diisocyanate (NCO), were introduced into a thermosetting resin (DGEBA). The flame retardancy properties of the composites were studied, and the results were compared with those of 5 wt% bis(bis(4-((diphenoxyphosphoryl)oxy)phenyl)methyl) 1,4-phenylenedicarbamate (DHPP-OH-NCO), 10 wt% DHPP-OH-NCO and 15 wt% DHPP-OH-NCO curing agents. The results showed that 15 wt% DHPP-OH-NCO had an improved flame retardancy, the limited oxygen index reached 33.5% and the vertical burning test (UL94) achieved a V-0 level. A cone calorimeter experiment showed that the addition of the flame retardant significantly reduced the amount of generated smoke and heat. Macroscopic digital images, scanning electron microscopy images and thermogravimetric analysis results further revealed that the epoxy resin (EP) with DHPP-OH-NCO exhibited greater char yields. The flame retardancy mechanism of the flame retardant was preliminarily shown by pyrolysis–gas chromatography–mass spectrometry analysis. The combined test results demonstrate that a high-efficiency phosphorous-containing flame retardant for EPs was successfully developed.

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Study on flame retardancy of TGDDM epoxy resin blended with inherent flame-retardant epoxy ether

High Performance Polymers ◽

10.1177/0954008317694077 ◽

2017 ◽

Vol 30 (3) ◽

pp. 318-327 ◽

Cited By ~ 5

Author(s):

Mengjiao Wang ◽

Shijiang Fang ◽

Heng Zhang

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

Decomposition Temperature ◽

Resin Matrix ◽

Thermal Stabilities ◽

Limiting Oxygen Index ◽

Diaminodiphenyl Sulfone ◽

Air Atmosphere ◽

Index Value

In this article, inherent flame-retardant epoxy ether, 9,10-dihydro-9-oxa-10-[1,1-bis(4-glycidyloxyphenyl)ethyl]-10-phosphaphenanthrene 10-oxide (DPBAEP), with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide moieties was synthesized via an economical method and was used to improve the flame retardancy of 4,4′-tetradiglycidyl diaminodiphenyl methane (TGDDM). A series of epoxy resins were prepared and cured with 4,4′-diaminodiphenyl sulfone. The glass transition temperatures ( Tg) of resin composites were above 243°C and decreased only slightly after DPBAEP was added. The thermal stabilities under the nitrogen (N2) and air atmosphere were also measured using thermogravimetric analysis. The results indicated that DPBAEP had a high decomposition temperature and affected the thermal degradation and promoted the charring of resins. When only over 5 wt% of DPBAEP was introduced, the thermosets obtained a high limiting oxygen index value of around 33.0%, achieved vertical burning V-0 rating and presented fast-swelling char barriers. In order to better understand the flame-retardant mechanisms, the residual char was investigated by scanning electron microscopy observation and Fourier transform infrared spectra. We inferred that the phosphorus (P) moieties reacted with the resin matrix, which played a significant role in promoting the formation of char with special structure, as well as making it rich and tough enough. This kind of char barrier could protect the underlying resin matrix against oxygen and heat transfer and inhibited volatile combustible from diffusing to the flame. Hence, thanks to the synergistic effect of P–N and the excellent compatibility, DPBAEP could impart excellent flame retardancy to TGDDM epoxy resin.

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A Study on the Synthesis, Curing Behavior and Flame Retardance of a Novel Flame Retardant Curing Agent for Epoxy Resin

Polymers ◽

10.3390/polym14020245 ◽

2022 ◽

Vol 14 (2) ◽

pp. 245

Author(s):

Yong Sun ◽

Yongli Peng ◽

Yajiao Zhang

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Decomposition Temperature ◽

Isothermal Kinetics ◽

Flame Retardance ◽

Curing Agent ◽

Initial Decomposition Temperature ◽

Limiting Oxygen Index ◽

Epoxy Resin System ◽

Dsc Method

In this work, a flame retardant curing agent (DOPO-MAC) composed of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and methyl acrylamide (MAC) was synthesized successfully, and the structure of the compound was characterized by FT-IR and 1H-NMR. The non-isothermal kinetics of the epoxy resin/DOPO-MAC system with 1% phosphorus was studied by non-isothermal DSC method. The activation energy of the reaction (Ea), about 46 kJ/mol, was calculated by Kissinger and Ozawa method, indicating that the curing reaction was easy to carry out. The flame retardancy of the epoxy resin system was analyzed by vertical combustion test (UL94) and limiting oxygen index (LOI) test. The results showed that epoxy resin (EP) with 1% phosphorus successfully passed a UL-94 V-0 rating, and the LOI value increased along with the increasing of phosphorus content. It confirmed that DOPO-MAC possessed excellent flame retardance and higher curing reactivity. Moreover, the thermal stability of EP materials was also investigated by TGA. With the DOPO-MAC added, the residual mass of EP materials increased remarkably although the initial decomposition temperature decreased slightly.

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Synthesis of a phosphorus–nitrogen-containing flame retardant and its application in epoxy resin

High Performance Polymers ◽

10.1177/0954008318756496 ◽

2018 ◽

Vol 31 (2) ◽

pp. 186-196 ◽

Cited By ~ 12

Author(s):

Shuang Yang ◽

Yefa Hu ◽

Qiaoxin Zhang

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Epoxy Resin ◽

Heat Release Rate ◽

Flame Retardancy ◽

Release Rate ◽

Epoxy Resins ◽

Proton Nuclear Magnetic Resonance ◽

Scanning Calorimetry ◽

Cone Calorimeter Test

In this article, a phosphorus–nitrogen-containing flame retardant (DOPO-T) was successfully synthesized by nucleophilic substitution reaction between 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and cyanuric chloride. The chemical structure of DOPO-T was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (NMR) and phosphorous-31 NMR, and elemental analysis. DOPO-T was then blended with diglycidyl ether of bisphenol-A to prepare flame-retardant epoxy resins. Thermal properties, flame retardancy, and combustion behavior of the cured epoxy resins were evaluated by differential scanning calorimetry, thermogravimetric analysis, limited oxygen index (LOI) measurement, UL94 vertical burning test, and cone calorimeter test. The results indicated that the glass transition temperature ( Tg) and temperature at 5% weight loss of epoxy resin (EP)/DOPO-T thermosets were gradually decreased with the increasing content of DOPO-T. DOPO-T catalyzed the decomposition of EP matrix in advance. The flame-retardant performance of EP thermosets was significantly enhanced with the addition of DOPO-T. EP/DOPO-T-0.9 sample had an LOI value of 36.2% and achieved UL94 V-1 rating. In addition, the average of heat release rate, peak of heat release rate, average of effective heat of combustion, and total heat release (THR) of EP/DOPO-T-0.9 sample were decreased by 32%, 48%, 23%, and 31%, respectively, compared with the neat EP sample. Impressively, EP/DOPO-T thermosets acquired excellent flame retardancy under low loading of flame retardant.

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

Journal of Engineered Fibers and Fabrics ◽

10.1177/1558925020901323 ◽

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.

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Flammability and thermal properties of cotton fabrics modified with a novel flame retardant containing triazine and phosphorus components

Textile Research Journal ◽

10.1177/0040517516652349 ◽

2016 ◽

Vol 87 (11) ◽

pp. 1367-1376 ◽

Cited By ~ 20

Author(s):

Chaohong Dong ◽

Zhou Lu ◽

Peng Wang ◽

Ping Zhu ◽

Xuechao Li ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Cotton Fabric ◽

Flame Retardancy ◽

Decomposition Temperature ◽

Cotton Fabrics ◽

Cone Calorimetry ◽

Limiting Oxygen Index ◽

Untreated Cotton ◽

Index Value

A novel formaldehyde-free flame retardant containing phosphorus and dichlorotriazine components (CTAP) for cotton fabrics was synthesized. As an active group, the dichlorotriazine could react with cotton fabric via covalent reaction. The addition of 20.7 wt% CTAP into the cotton fabric obtained a high limiting oxygen index value of 31.5%, which was 13.5% higher than the pure cotton fabric. The results of heat release rate, total heat release and effective heat combustion indicated that CTAP effectively imparted flame retardancy to cotton fabric by the cone calorimetry test. With respect to the untreated cotton fabrics, the treated cotton fabrics degraded at lower decomposition temperature and form a consistent and compact char layer, which could be observed by thermogravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. Compared to the untreated cotton fabrics, CTAP performed an effective role in flame retardancy for treated cotton fabrics. Meanwhile, it stimulated the formation of char and promoted the thermal stability of treated cotton fabrics during combustion.

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Synergistic Flame Retardant Effect of Barium Phytate and Intumescent Flame Retardant for Epoxy Resin

Polymers ◽

10.3390/polym13172900 ◽

2021 ◽

Vol 13 (17) ◽

pp. 2900

Author(s):

Linyuan Wang ◽

Yue Wei ◽

Hongbo Deng ◽

Ruiqi Lyu ◽

Jiajie Zhu ◽

...

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

Barium Carbonate ◽

Environmentally Friendly ◽

Intumescent Flame Retardant ◽

Limiting Oxygen Index ◽

Application Range ◽

Peak Heat Release Rate ◽

Synergistic Flame Retardant

Recently, widespread concern has been aroused on environmentally friendly materials. In this article, barium phytate (Pa-Ba) was prepared by the reaction of phytic acid with barium carbonate in deionized water, which was used to blend with intumescent flame retardant (IFR) as a flame retardant and was added to epoxy resin (EP). Afterward, the chemical structure and thermal stability of Pa-Ba were characterized by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA), respectively. On this basis, the flammability and flame retardancy of EP composites were researched. It is shown that EP/14IFR/2Ba composite has the highest limiting oxygen index (LOI) value of 30.7%. Moreover, the peak heat release rate (PHRR) of EP/14IFR/2Ba decreases by 69.13% compared with pure EP. SEM and Raman spectra reveal the carbonization quality of EP/14IFR/2Ba is better than that of other composites. The results prove that Pa-Ba can cooperate with IFR to improve the flame retardancy of EP, reducing the addition amount of IFR in EP, thus expanding the application range of EP. In conclusion, adding Pa-Ba to IFR is a more environmentally friendly and efficient method compared with others.

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Novel P/Si Based Nanoparticles for Durable Flame Retardant Application on Cotton

10.21203/rs.3.rs-585202/v1 ◽

2021 ◽

Author(s):

Na Li ◽

Panpan Chen ◽

Dongni Liu ◽

Gaowei Kang ◽

Liu Liu ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Oxygen Index ◽

Dip Coating ◽

Gas Chromatography Mass Spectrometry ◽

Cotton Fibers ◽

Pyrolysis Gas ◽

Limiting Oxygen Index ◽

Potential Safety ◽

Ft Ir

Abstract Cotton fibers as original materials of cotton fabrics have a widely application due to its perfect hygroscopicity, air permeability and largest annual output. However, cotton materials have potential safety hazard during its application because of flammability (limiting oxygen index is about 18%). In order to improve the flame retardancy of cotton fibers and reduce the damage of its mechanical properties, novel P/Si based flame retardant (PFR) nanoparticles were synthesized by one-step radical polymerization. Vinyl phosphoric acid and tetramethyl divinyl disiloxane were introduced into the nanoparticles. The structure, morphology and thermal stability of PFR was characterized by fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis test (TGA). Durable flame retardant cotton fibers were prepared by dip-coating and plasma induced crosslinking methods. Micro-calorimeter (MCC) characterization showed that the peak of heat release rate (pHRR) and the total heat release were reduced by 47.3% and 29.8% for modified cotton fibers compared with pure cotton fibers. Limiting oxygen index (LOI) of modified cotton fibers was increased to 27%. The residue carbon of modified cotton fibers was 19.0% at 700 o C, while the value of pure cotton fibers was 3.0%. Besides, durability of the modified cotton fibers was approved by cyclic washing test. In addition, flame retardant mechanism was revealed by collecting and analyzing condensed and gaseous pyrolysis products. The data of FE-SEM for residue carbon, FT-IR spectra of products at different pyrolysis temperatures and pyrolysis gas chromatography mass spectrometry (Py-GC-MS) showed that PFR was a synergistic flame retardant contained barrier and quenching effecting applied on cotton materials.

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