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

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.

2020 ◽  
Vol 15 ◽  
pp. 155892502090132
Author(s):  
Sang-Hoon Lee ◽  
Seung-Won Oh ◽  
Young-Hee Lee ◽  
Il-Jin Kim ◽  
Dong-Jin Lee ◽  
...  

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.


2020 ◽  
Vol 38 (4) ◽  
pp. 333-347
Author(s):  
Lichen Zhang ◽  
Deqi Yi ◽  
Jianwei Hao

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.


Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 245
Author(s):  
Yong Sun ◽  
Yongli Peng ◽  
Yajiao Zhang

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.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1708 ◽  
Author(s):  
Wang ◽  
Teng ◽  
Yang ◽  
You ◽  
Zhang ◽  
...  

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.


2020 ◽  
Vol 842 ◽  
pp. 314-325
Author(s):  
Bin Lin

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.


2010 ◽  
Vol 150-151 ◽  
pp. 727-731 ◽  
Author(s):  
Zhi Yi Huang ◽  
Shao Rong Lu ◽  
Zhi You Yang ◽  
Chun He Yu ◽  
Dong Guo

Liquid crystal polyurethane (LCPBI) containing biphenylnate and imide units was synthesized and characterized and used to modify the conventional epoxy resin (E-51). Experimental results revealed that the impact strength of the epoxy resin modified with LCPBI was 2.5 times higher than that of unmodified epoxy resin, and the tensile strength as well as the bending strength was also improved. The thermal decomposition temperature of modified systems was also 15-20oC higher than that of the unmodified system, and the fracture structures of the blends was investigated by SEM.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3221
Author(s):  
Feiyue Wang ◽  
Jiahao Liao ◽  
Long Yan ◽  
Hui Liu

A novel diaminodiphenylmethane (DDM) modified ammonium polyphosphate (APP) flame retardant, DDP, was successfully synthesized via ion-exchange reaction. DDP was introduced into epoxy resins (EPs) to reduce flammability. A comparable level of DDP exerts better flame-retardant and smoke suppression efficiencies in EP than APP. An EP blend containing 15 wt% DDP displays a limiting oxygen index (LOI) value of 37.1% and a UL 94 V-0 rating, and further exhibits a 32.3% reduction in total heat release and a 48.0% reduction in total smoke production compared with pure EP. The presence of DDP greatly facilitates char formation during combustion, and the char mass from thermal decomposition of an EP blend is 37.8% smaller than that of an EP blend containing 15 wt% DDP at 800 °C. The incorporation of DDP into EP blends has a smaller impact on the glass transition temperature and tensile strength than those of a comparable level of APP. This reflects the better compatibility of DDP with the EP matrix compared with that for APP.


2021 ◽  
Author(s):  
Yonggang Du ◽  
Gonghui Shi ◽  
Hui Wang ◽  
Ge Zhao ◽  
Wei Li ◽  
...  

Abstract The novel bio-based epoxy resin based on naringenin was synthesized. The naringenin epoxy/UiO-66 composites were prepared by casting process with UiO-66 as modifier and maleic anhydride as curing agent. The influences of UiO-66 content on mechanical properties, thermal stability and flame retardancy of naringenin epoxy/UiO-66 composites were investigated. The results showed that the impact strength, glass transition temperature and limiting oxygen index of pure naringenin epoxy resin were 2.0 kJ/m2, 96 ℃ and 1.2% higher than that of di-glycidyl ether of bisphenol A (DGEBA), respectively. UiO-66 can significantly improve the impact strength of naringenin epoxy resin while assisting improve its flame retardancy. When UiO-66 content was 4 wt%, the impact strength and limiting oxygen index of the naringenin epoxy/UiO-66 composite were 7.6 kJ/m2 and 24.5%, which were 85.4% and 3.5% higher than that of pure naringin epoxy resin, respectively.


2012 ◽  
Vol 466-467 ◽  
pp. 495-499 ◽  
Author(s):  
Ming Gao ◽  
Ying Juan Sun

A novel cheap macromolecular intumescent flame retardants (Zn-MIFR), was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus-silicon characterized by IR. Epoxy resins (EP) were modified with Zn-MIFR to get the flame retardant EP, whose flammability and burning behavior were characterized by UL 94, limiting oxygen index (LOI), dilatation, char yield, smoke density rating (SDR) and maximum smoke density (MSD). The epoxy resins were obtained for the UL 94 V-0 rating at low Zn contents of 3.0 % get a LOI of 27.5% and char yield of 20.5%. Dilatation, SDR and MSD of EP/Zn-MIFR decreased. The degradation behavior of the EP/Zn-MIFR was studied by TG and EDX analysis. The experimental results exhibited that the initial decomposition temperature (IDT) was decreased, integral procedure decomposition temperature (IPDT) and amounts of Zn and P at the residue were increased.


2012 ◽  
Vol 586 ◽  
pp. 172-176
Author(s):  
Hao Ran Zhou ◽  
Hao Cheng Yang ◽  
An Sun ◽  
Shuang Zhao

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.


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