Intumescent flame retardancy of a DGEBA epoxy resin based on 5,10-dihydro-phenophosphazine-10-oxide

RSC Advances ◽  
2015 ◽  
Vol 5 (84) ◽  
pp. 68476-68484 ◽  
Author(s):  
Qinqin Luo ◽  
Yanchao Yuan ◽  
Chunlei Dong ◽  
Shumei Liu ◽  
Jiangqing Zhao

Only 2.5 wt% DPPA makes the epoxy resin achieve a V-0 rating in the UL-94 test due to the combination of intumescent charring and the blowing-out effect.

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3496
Author(s):  
Junming Geng ◽  
Jianyu Qin ◽  
Jiyu He

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.


10.6036/10327 ◽  
2022 ◽  
Vol 97 (1) ◽  
pp. 98-103
Author(s):  
XIAN WANG ◽  
JINLONG ZHUO ◽  
TIANQING XING ◽  
Xingran Wang

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


2017 ◽  
Vol 30 (2) ◽  
pp. 202-210 ◽  
Author(s):  
Rasool Kheyrabadi ◽  
Hossein Rahmani ◽  
S Heydar Mahmoudi Najafi

Flame-retardant halogen-free epoxy resin, containing phosphorus and nitrogen atoms in the main chain, was synthesized through the curing of tris(3-(bis(oxiran-2-ylmethyl)amino)phenyl)phosphine oxide (HGE, hexaglycidyl epoxy monomer), starting from tris(3-aminophenyl) phosphine oxide (TAPO) and epichlorohydrin. The molecular structure of HGE with molecular weight 660 was confirmed using Fourier transform infrared, nuclear magnetic resonance, and liquid chromatography–mass spectrometry techniques. Epoxy equivalent weight determined by titration method was 120. The thermal curing behavior of the HGE/TAPO was investigated by differential scanning calorimetry. An intense exotherm due to curing reaction was observed in the temperature range from 123°C to 215°C. The HGE cured with TAPO, 4,4′-diaminodiphenylsulfone (DDS), and 1,5-diaminonaphthalene (DAN) and the thermal behaviors were studied by thermogravimetric analysis. The flame retardancy properties of the HGE/TAPO, DDS, and DAN were evaluated by vertical burning test (UL-94 V). The high performance cured epoxy resins showed high thermal stability and UL-94 V-0 flame retardancy rating.


2013 ◽  
Vol 652-654 ◽  
pp. 84-88
Author(s):  
Jian Xiong Wei ◽  
Gui Long Xu ◽  
Jian Hu ◽  
Jin Yang

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.


2021 ◽  
Vol 2 (1) ◽  
pp. 24-48
Author(s):  
Quoc-Bao Nguyen ◽  
Henri Vahabi ◽  
Agustín Rios de Anda ◽  
Davy-Louis Versace ◽  
Valérie Langlois ◽  
...  

This study has developed novel fully bio-based resorcinol epoxy resin–diatomite composites by a green two-stage process based on the living character of the cationic polymerization. This process comprises the photoinitiation and subsequently the thermal dark curing, enabling the obtaining of thick and non-transparent epoxy-diatomite composites without any solvent and amine-based hardeners. The effects of the diatomite content and the compacting pressure on microstructural, thermal, mechanical, acoustic properties, as well as the flame behavior of such composites have been thoroughly investigated. Towards the development of sound absorbing and flame-retardant construction materials, a compromise among mechanical, acoustic and flame-retardant properties was considered. Consequently, the composite obtained with 50 wt.% diatomite and 3.9 MPa compacting pressure is considered the optimal composite in the present work. Such composite exhibits the enhanced flexural modulus of 2.9 MPa, a satisfying sound absorption performance at low frequencies with Modified Sound Absorption Average (MSAA) of 0.08 (for a sample thickness of only 5 mm), and an outstanding flame retardancy behavior with the peak of heat release rate (pHRR) of 109 W/g and the total heat release of 5 kJ/g in the pyrolysis combustion flow calorimeter (PCFC) analysis.


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