Transparent low-flammability epoxy resins using a benzoguanamine-based DOPO derivative

2021 ◽  
pp. 095400832110499
Author(s):  
Xiao Han ◽  
Rui Chen ◽  
Mei Yang ◽  
Chuanbo Sun ◽  
Kun Wang ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Cone Calorimeter ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Control Group ◽  
Limited Oxygen Index ◽  
Cone Calorimeter Test ◽  
Limited Oxygen

We successfully prepared a highly effective flame-retardant additive called hsalbenzoguanamine phosphaphenanthrene (HDPD) through salicylaldehyde and nitrogen-rich benzoguanamine. The introduction of HDPD into epoxy resin (EP) sharply enhanced the flame retardancy of EP/HDPD thermosets. The introduction of 6 wt% HDPD into EP succeeded in reaching the V-0 rating. Limited oxygen index results revealed the high flame-retarding performance of HDPD. Cone calorimeter test data revealed that heat and smoke released from EP/6 wt% HDPD thermoset were significantly restrained. In addition, EP/6 wt% HDPD thermoset demonstrated excellent transmittance and mechanical strength. The transmittance of EP/6 wt% HDPD was assessed from 520 to 800 nm. The results showed that transmittance of EP/6 wt% HDPD were nearly 90% of the control group.

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

2018 ◽  
Vol 31 (2) ◽  
pp. 186-196 ◽  
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.

Flame retardancy and thermal properties of rigid polyurethane foam conjugated with a phosphorus–nitrogen halogen-free intumescent flame retardant

2020 ◽  
Vol 38 (3) ◽  
pp. 235-252
Author(s):  
Zhaojun Lin ◽  
Qianqiong Zhao ◽  
Ruilan Fan ◽  
Xiaoxue Yuan ◽  
Fuli Tian
Keyword(s):  
Thermal Properties ◽  
Thermogravimetric Analysis ◽  
Flame Retardant ◽  
Polyurethane Foam ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Carbon Layer ◽  
Limited Oxygen Index ◽  
Halogen Free ◽  
Limited Oxygen

In this work, a halogen-free intumescent combining phosphorus and nitrogen, flame-retardant 2-((2-hydroxyphenyl)(phenylamino)methyl5,5-dimethyl-1,3,2-dioxaphosphinane 2-oxide (HAPO) was successfully synthesized. It had been synthesized by reaction of 5,5-dimethyl-1,3, 2-dioxphosphinane 2-oxide with Schiff base. Its chemical structure was characterized in detail by Fourier transform infrared spectroscopy, 1H NMR, and 31P NMR spectrum. The flame-retardant polyurethanes were prepared with different loadings of HAPO. The thermal properties, flame retardancy and combustion behavior of the pure polyurethane foam thermosets were investigated by a series of measurements involving thermogravimetric analysis, limited oxygen index measurement, UL-94 vertical burning test, and cone calorimeter test. The results of the aforementioned tests indicated that HAPO can significantly improve the flame retardancy as well as smoke inhibition performance of polyurethane foam. Compared with the PU-Neat, the limited oxygen index of flame-retardant polyurethanes (15%) thermoset was increased from 19.5% to 23.8% and its UL-94 reached V-0 rating. In addition, the cone test results showed that the heat release rate, total heat release, rate of smoke release, and total smoke production of flame-retardant polyurethanes (10%) were decreased obvious sly. The apparent morphology of carbon residue was characterized by scanning electron microscopy, and results revealed that the modified polyurethane foam can form dense carbon layer after combustion. Thermogravimetric analysis results also indicated that the char amount of flame-retardant polyurethanes was obviously increased compared with PU-Neat. Based on the above analysis, we can draw the conclusions which in the condensed phase, phosphorus-based acids from the degradation of HAPO, this could promote the formation of continuous and dense phosphorus-rich carbon layer. In the gas phase, the flame-retardant mechanism was ascribed to the quenching effect of phosphorus-based radicals and diluting effect by non-flammable gases.

Synergistic Effect between Montmorillonite Intercalated by Melamine and Intumescent Flame Retardant (IFR) on Polypropylene

2011 ◽  
Vol 295-297 ◽  
pp. 315-318
Author(s):  
Hong Fang Zhu ◽  
Juan Li ◽  
Liang Xu ◽  
Kang Tao ◽  
Li Xin Xue ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Flame Retardant ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Intumescent Flame Retardant ◽  
Limited Oxygen Index ◽  
Cation Exchange Reaction ◽  
Melamine Salt ◽  
Better Than ◽  
Limited Oxygen

This Montmorillonite modified by melamine (MA-MMT) was prepared via cation exchange reaction by using melamine salt as intercalation reagent. MA-MMT and Na-MMT was combined with intumescent flame retardant (IFR) to be adopted into polypropylene (PP), respectively. The synergistic effect between MA-MMT and IFR and the influence of melamine in MMT layers on fire-resistant performance was evaluated. Results of limited oxygen index (LOI) tests and UL-94 tests indicate that melamine salts in MMT layers behaved better than Na-MMT in PP/IFR system. According to the results of cone calorimeter tests and scanning electron microscope (SEM), it concludes that melamine salts act as gas agent to provide migration impetus and expanded power, which caused a well-structured and strong char that had better ability to endure heat erosion. A good synergistic effect between MA-MMT and IFR is constructed.

Improved flame retardancy and thermal stability of P- and N-containing diphenol epoxy resins from lignin oxidation degraded derivatives

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 529-545
Author(s):  
Liqing Zhu ◽  
Jiewang Ye ◽  
Weimiao Lu ◽  
Yan Zhang ◽  
Zhenfu Jin
Keyword(s):  
Epoxy Resin ◽  
Flame Retardancy ◽  
Photoelectron Spectroscopy ◽  
Epoxy Resins ◽  
Carbon Layer ◽  
Raw Material ◽  
Spectroscopy Analysis ◽  
Nuclear Magnetic Resonance Spectra ◽  
Cone Calorimeter Test ◽  
Thermal Stability Of

Diphenols with structures similar to bisphenol A (BPA) were designed and synthesized from three kinds of lignin oxidative depolymerized derivatives (LODD) to investigate the substitution possibility of BPA by LODD as raw material. The chemical shift and integral area of nuclear magnetic resonance spectra and the X-ray photoelectron spectroscopy analysis results showed that phosphorus- and nitrogen-containing diphenols were successfully formed. The cone calorimeter test and thermogravimetric analysis exhibited that the epoxy resin from diphenols were typical intumescent flame retardancy systems. These results showed drastically improved flame retardancy compared with traditional epoxy resin. Among them, the epoxy resin derived from vanillin presented the best flame retardancy properties. Due to a phosphorus-rich carbon layer being formed and accumulated at the surface of the epoxy resins from diphenols, the thermal degradation showed great enhancement of the char residues.

scholarly journals Development and Characterization of Novel Fore Safe Epoxy Resins

2009 ◽  
Vol 3 (4) ◽  
pp. 269-276
Author(s):  
Zbigniew K. Brzozowski ◽  
◽  
Sylwia Staszczak ◽  
Pawel Koziol ◽  
Wojciech Zatorski ◽  
...  
Keyword(s):  
Solid State ◽  
Bisphenol A ◽  
Epoxy Resins ◽  
Flame Retardants ◽  
Oxygen Index ◽  
Diglycidyl Ether ◽  
Limited Oxygen Index ◽  
Microwave Reactor ◽  
Limited Oxygen

The curing system for newly developed solid state fire safe epoxy resins using dicyandiamide (DICY) was introduced. Composites of epoxy resins obtained from diglycidyl ether of 1,1-dichloro-2,2bis(4-hydroxyphenyl)ethylene bisphenol-C (BPC) and bisphenol-A (BPA) epoxy resins in the reaction with BPC and BPA and DICY hardener were studied. Solid epoxy resins were synthesised by the use of two different heating methods: conventional and microwave reactor. The quantities of DICY additions were 0.5–5.0 %, optimum was found to be 3 %. Limited oxygen index (OI) tests for different epoxy resins and addition of flame – retardants were carried out. The highest value of OI was 34.6. As additional flame-retardants were used zinc stannates (ZS, ZHS). Evident OI increase was noted from 27.0 for classical epoxies, 34.6 for BPC cured epoxies and 44 for cured composites with the addition of Zn/Sn flame-retardants.

scholarly journals Investigating the Effect of Aluminum Diethylphosphinate on Thermal Stability, Flame Retardancy, and Mechanical Properties of Poly(butylene succinate)

2021 ◽  
Vol 8 ◽  
Author(s):  
Yiming Wang ◽  
Dayong Jiang ◽  
Xin Wen ◽  
Tao Tang ◽  
Karolina Szymańska ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Butylene Succinate ◽  
Air Atmosphere ◽  
Cone Calorimeter Test ◽  
Filler Dispersion ◽  
Thermal Stability Of ◽  
Limited Oxygen

Poly(butylene succinate) is one of the most promising biodegradable polymers, but its applications are limited by poor flame retardancy. In this work, poly(butylene succinate)/diethylphosphinate (PBS/AlPi) composites were fabricated to investigate the effect of AlPi on their thermal stability, flame retardancy, and mechanical properties. It was found that the high content of AlPi decreased the thermal stability of PBS, and the decrease became stronger under the air atmosphere. When the content of AlPi reached 25wt%, the flame retardancy was improved with limited oxygen index (LOI) of 29.5%, V0 rating in UL-94 vertical burning test, and 49.3% reduction on the peak of heat release rate (PHRR) in cone calorimeter test. Meanwhile, the addition of AlPi could improve the mechanical properties of PBS with high tensile strength and Young’s modulus, which was ascribed to the compatible effect of maleic anhydride-grafted poly(butylene succinate) (PBS-g-MA) with good filler dispersion and strong matrix-particles interaction. Thus, the AlPi was an effective flame retardant to PBS, so that PBS/AlPi composites displayed excellent flame retardancy without seriously sacrificing other comprehensive performances.

Synthesis of a Flame Retardant for Epoxy Resins: Thermal Stability, Flame Retardancy, and Flame-Retardant Modes

2021 ◽  
Vol 36 (2) ◽  
pp. 172-184
Author(s):  
Y. Zhang ◽  
J. Liu ◽  
S. Li
Keyword(s):  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Heat Release ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Limited Oxygen Index ◽  
Index Value ◽  
Limited Oxygen

Abstract A polyphosphonate (PDPA) flame retardant that contains phenyl phosphonic dichloride and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide groups, has been synthesized. The flame retardant was introduced into epoxy resins (EP) and cured by 4,4’-diamino diphenylmethane. The vertical burning, limited-oxygen index and cone calorimeter tests reveal that the PDPA can enhance the flame-retardant properties of the EP significantly. With only a 4 wt% PDPA loading, the EP composites achieved a limited-oxygen index value of 33.4% and a V-0 rating in the vertical burning test, and the peak heat release rate and total heat release were decreased by 40.9% and 24.6%, respectively. The thermal properties and gas pyrolysis products of the EP composites were evaluated by thermogravimetric analysis and thermogravimetric analysis-Fourier transform infrared spectroscopy, and the morphology and structure of residual char were characterized by scanning electron microscopy, Flourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. To explain the combined effects of the condensed and gas phases, modes of the flame-retardant action are proposed.

scholarly journals The Effect of Ultrafine Magnesium Hydroxide on the Tensile Properties and Flame Retardancy of Wood Plastic Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhiping Wu ◽  
Na Hu ◽  
Yiqiang Wu ◽  
Shuyun Wu ◽  
Zu Qin
Keyword(s):  
Thermogravimetric Analysis ◽  
Tensile Properties ◽  
Magnesium Hydroxide ◽  
Flame Retardancy ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Combustion Process ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
Cone Calorimeter Test

The effect of ultrafine magnesium hydroxide (UMH) and ordinary magnesium hydroxide (OMH) on the tensile properties and flame retardancy of wood plastic composites (WPC) were investigated by tensile test, oxygen index tester, cone calorimeter test, and thermogravimetric analysis. The results showed that ultrafine magnesium hydroxide possesses strengthening and toughening effect of WPC. Scanning electron micrograph (SEM) of fracture section of samples provided the positive evidence that the tensile properties of UMH/WPC are superior to that of WPC and OMH/WPC. The limited oxygen index (LOI) and cone calorimeter test illustrated that ultrafine magnesium hydroxide has stronger flame retardancy and smoke suppression effect of WPC compared to that of ordinary magnesium hydroxide. The results of thermogravimetric analysis implied that ultrafine magnesium hydroxide can improve the char structure which plays an important role in reducing the degradation speed of the inner matrix during combustion process and increases the char residue at high temperature.

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

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.

scholarly journals An Effective Method for Preparation of Liquid Phosphoric Anhydride and Its Application in Flame Retardant Epoxy Resin

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2205
Author(s):  
Qian Li ◽  
Yujie Li ◽  
Yifan Chen ◽  
Qiang Wu ◽  
Siqun Wang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Decomposition Temperature ◽  
Ease Of Use ◽  
Limiting Oxygen Index ◽  
Good Thermal Stability ◽  
Low Viscosity ◽  
The Impact

A novel liquid phosphorous-containing flame retardant anhydride (LPFA) with low viscosity was synthesized from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and methyl tetrahydrophthalic anhydride (MeTHPA) and further cured with bisphenol-A epoxy resin E-51 for the preparation of the flame retardant epoxy resins. Both Fourier transform infrared spectroscopy (FT-IR), mass spectrometry (MS) and nuclear magnetic resonance (NMR) measurements revealed the successful incorporation of DOPO on the molecular chains of MeTHPA through chemical reaction. The oxygen index analysis showed that the LPFA-cured epoxy resin exhibited excellent flame retardant performance, and the corresponding limiting oxygen index (LOI) value could reach 31.2%. The UL-94V-0 rating was achieved for the flame retardant epoxy resin with the phosphorus content of 2.7%. With the addition of LPFA, the impact strength of the cured epoxy resins remained almost unchanged, but the flexural strength gradually increased. Meanwhile, all the epoxy resins showed good thermal stability. The glass transition temperature (Tg) and thermal decomposition temperature (Td) of epoxy resin cured by LPFA decreased slightly compared with that of MeTHPA-cured epoxy resin. Based on such excellent flame retardancy, low viscosity at room temperature and ease of use, LPFA showed potential as an appropriate curing agent in the field of electrical insulation materials.

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