Surface Functionalization of Black Phosphorus via Amine Compounds and Its Impacts on the Flame Retardancy and Thermal Decomposition Behaviors of Epoxy Resin

Recently, lots of effort has been placed into stabilizing black phosphorus (BP) in the air to improve its compatibility with polymers. Herein, BP was chemically functionalized by aliphatic amine (DETA), aromatic amine (PPDA) and cyclamine (Pid) via a nucleophilic substitution reaction, aiming to develop an intensively reactive BP flame retardant for epoxy resin (EP). The -NH2 group on BP-DETA, BP-PPDA and BP-Pid reacted with the epoxide group at different temperatures. The lowest temperature was about 150 °C for BP-DETA. The impacts of three BP-NH2 were compared on the flame retardancy and thermal decomposition of EP. At 5 wt% loading, EP/BP-NH2 all passed UL 94 V 0 rating. The limiting oxygen index (LOI) of EP/BP-PPDA was as high as 32.3%. The heat release rate (HRR) of EP/BP-DETA greatly decreased by 46% and char residue increased by 73.8%, whereas HRR of EP/BP-Pid decreased by 11.5% and char residue increased by 50.8%, compared with EP. Average effective heat of combustion (av-EHC) of EP/BP-Pid was lower than that of EP/BP-DETA and EP/BP-PPDA. In view of the flame-retardant mechanism, BP nanosheets functionalized with aliphatic amine and aromatic amine played a dominant role in the condensed phase, while BP functionalized with cyclamine was more effective in the gas phase.

Download Full-text

The Flammability of Polyacrylonitrile and Its Copolymers I. The Flammability Assessment Using Pressed Powdered Polymer Samples

Journal of Fire Sciences ◽

10.1177/073490419301100505 ◽

1993 ◽

Vol 11 (5) ◽

pp. 442-456 ◽

Cited By ~ 14

Author(s):

Jun Zhang ◽

Michael E. Hall ◽

A. Richard Horrocks

Keyword(s):

Flame Retardant ◽

Flame Retardancy ◽

Flame Retardants ◽

Oxygen Index ◽

Char Residue ◽

Acrylic Polymer ◽

Limiting Oxygen Index ◽

Convenient Means ◽

Burning Rates ◽

Polymer Flammability

This paper is the first in a series of four which investigates the burning behaviour and the influence of flame retardant species on the flam mability of fibre-forming polymer and copolymers of acrylonitrile. A pressed powdered polymer sheet technique is described that enables a range of polymer compositions in the presence and absence of flame retardants to be assessed for limiting oxygen index, burning rate and char residue deter minations. The method offers a rapid, reproducible and convenient means of screening possible flame retardant systems, and LOI values compare favourably with those of films and fabrics comprising the same polymeric type. Burning rates, however, are sensitive to changes in physical sample character such as form (film vs. powder sheet) and density. Thus the technique forms an excellent basis for the generation of burning data which will enable comprehensive studies of acrylic polymer flammability and flame retardancy to be undertaken.

Download Full-text

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.

Download Full-text

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.

Download Full-text

Synthesis of a Flame Retardant and Hydrophobic Epoxy Resin with Multiple Elements Synergistic Effect for Tunnel Seepage Prevention Application

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.842.314 ◽

2020 ◽

Vol 842 ◽

pp. 314-325

Author(s):

Bin Lin

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

Oxygen Index ◽

Fire Retardant ◽

Practical Application ◽

Water Contact ◽

Limiting Oxygen Index ◽

New Perspective ◽

Grouting Materials

Epoxy resin (EP) mortar usually used to repair the cracking of concrete structure under damp environment, but EP is extremely flammable, thus it’s extremely imperative to design a novel multifunction EP grouting materials with flame retardancy and waterproofness for the practical application. Targeting ingenious decoration of EP grouting materials, multiple flame retardant elements (phosphorus, nitrogen and fluorine) are concurrently introduced into a fire retardant and the fire retardant defined as DDM-FNP. The obtained DDM-FNP/EP grouting composite possess high thermal stability, flame retardancy and hydrophobicity. The limiting oxygen index (LOI) value of DDM-FNP/EP composites has a significant improve, which is increased from 26.7 (EP-0) to 35.8 (EP-4). Composites with more than 10 wt% of DDM-FNP could pass UL-94 V-0 rating without dripping. Compared with EP-0, the PHRR and THR of EP-4 are decreased by 31.1% and 21.6%, respectively. In addition, due to the introduction of the F element, the water contact angle of EP composites is changed from 75.2° (hydrophilicity) to 98.6° (hydrophobicity) after the introduction of a certain amount of DDM-FNP flame retardant. Therefore, this work provide a new perspective to design a multifunction EP grouting composite and improve the value of practical application on seepage prevention of tunnel.

Download Full-text

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

Download Full-text

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

High Performance Polymers ◽

10.1177/0954008319867369 ◽

2019 ◽

Vol 32 (4) ◽

pp. 359-370 ◽

Cited By ~ 1

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.

Download Full-text

Flame Retardant Epoxy Resin Containing Magnesium Phosphinate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.1927 ◽

2013 ◽

Vol 634-638 ◽

pp. 1927-1930 ◽

Cited By ~ 1

Author(s):

Jia Chen ◽

Ji Yan Liu ◽

Xue Qing Liu ◽

Shan Sun

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

Oxygen Index ◽

Limiting Oxygen Index ◽

Gas Source ◽

Char Formation ◽

Higher Temperature ◽

Preliminary Study ◽

Thermal Stability Of

In this paper, magnesium methylcyclohexylphosphinate (Mg(MHP)) was used as flame retardant for epoxy resin(EP).The flame retardancy and thermal stability of Mg(MHP)/EP composites have been studied. As a result, the composite with 20-25% Mg(MHP) can achieve the satisfying flame retardancy with the limiting oxygen index (LOI) of 29.05 % and passing the UL-94 V-0 rating. TG results showed that adding Mg(MHP) into EP leads to a increase in the onset temperature of degradation and depresses the thermal decomposition below around 470 °C. Beyond 470 °C, the residue char of the composites lost more quickly compared to neat EP. A preliminary study seem to conclude that Mg(MHP) acts as the condensed source by promoting the char formation below around 470 oC and as the gas source by vaporizing at higher temperature.

Download Full-text

Study on Properties of a Novel Flame Retardant Epoxy Curing Agent

Materials Science Forum ◽

10.4028/www.scientific.net/msf.953.179 ◽

2019 ◽

Vol 953 ◽

pp. 179-184

Author(s):

Yong Li Peng ◽

Can Zhang ◽

Ni An Zhuo

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

Mass Fraction ◽

Oxygen Index ◽

Raw Materials ◽

Curing Agent ◽

Resin System ◽

Limiting Oxygen Index ◽

Epoxy Curing

Using 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10 oxide (DOPO) and N-methylol acrylamide as the main raw materials, the curing agent DOPO-NMA was synthesized. The flame retardant curing agent DOPO-NMA and E-51 epoxy resin (EP) were then cured to obtain epoxy resin E-51 system, and its flame retardancy, thermal stability and mechanical properties were studied. The results showed that the tensile, bending and impact strength of the cured system decreased with the increase of phosphorus mass fraction in the resin system, and the flame retardancy rating, limiting oxygen index (LOI) and char yield at 700°C increased with the increase of phosphorus mass fraction in the resin system.

Download Full-text

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

High Performance Polymers ◽

10.1177/0954008321992412 ◽

2021 ◽

pp. 095400832199241

Author(s):

Zijin Luo ◽

Zhe Chen ◽

Jun Wei ◽

Dongchao Wang ◽

Han Chen ◽

...

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

Gas Chromatography Mass Spectrometry ◽

Control Group ◽

Pyrolysis Gas ◽

Limiting Oxygen Index ◽

Cone Calorimeter Test ◽

Epoxy Resin System ◽

Index Value

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.

Download Full-text

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.

Download Full-text