Effect of ethyl‐bridged diphenylphosphine oxide on flame retardancy and thermal properties of epoxy resin

Three commercialized flame retardants, 1,2‐bis(diphenylphosphinoyl)ethane (EDPO), 6,6‐(1,2‐phenethyl)bis‐6H‐dibenz[c,e][1,2]oxaphosphorin‐6,6‐dioxide (HTP‐6123), and hexa‐phenoxy‐cyclotriphosphazene (HPCTP), were used to prepare the flame retardant diglycidyl ether of bisphenol A (DGEBA) epoxy resin (EP) under the same experimental conditions. The effects of T_g, thermal stability, and water absorption properties of EP caused by the three flame retardants were investigated and compared, together with their flame retardant efficiency. Results showed that the introduction of the three flame retardants improved the flame retardant performance of EP but led to decreases in T_g and decomposition temperature. EDPO showed higher flame retardant efficiency than the other two flame retardants. EP/EDPO showed higher thermal stability, better flame retardant performance, higher T_g value, and lower water absorption than EP/HTP‐6123 and EP/HPCTP. The study discovered that EDPO and HTP‐6123 primarily act through the gas phase flame retardant mechanism, while HPCTP is primarily driven by the condensed phase mechanism.     

A vanillin-derived flame retardant based on 2-aminopyrimidine for enhanced flame retardancy and mechanical properties of epoxy resin

In order to give epoxy resin good flame retardance, a novel bio-based flame retardant based on 2-aminopyrimidine (referred to as VAD) was synthesized from renewable vanillin as one of the starting materials. Its structure was confirmed by NMR and mass spectra. The epoxy resins containing VAD were prepared by utilizing 4,4-diaminodiphenylmethane (DDM) as a co-curing agent, and their flame-retardant, mechanical and thermal properties and corresponding mechanisms were studied. VAD accelerated the cross-linking reaction of DDM and E51 (diglycidyl ether of bisphenol A). 12.5 wt% VAD made the epoxy resin achieve UL-94 V-0 rating and its limited oxygen index (LOI) value increase from 22.4% to 32.3%. The cone calorimetric testing results revealed the decline in the values of total heat release (THR) and peak of heat release rate (pk-HRR) and the obvious enhancement of residue yield. A certain amount of VAD enhanced the flame inhibition, charring and barrier effects, resulting in good flame retardance of the epoxy resin. Furthermore, the tensile strength, flexural strength and flexural modulus of the epoxy resin with 12.5 wt% loading of VAD were 6.5%, 14.9%, 15.2% higher than those of EP, indicating the strengthening effect of VAD. This work guarantees VAD to be a promising flame retardant for enhancing the fire retardancy of epoxy resin without compromising its mechanical properties.     

Preparation of (Fe)MIL-101 on short carbon fibers to improve the flame retardancy,smoke suppression,and mechanical of epoxy resin

Nano (Fe)MIL-101 particles were grafted on the short carbon fibers (SCFs) by in situ growth method to prepare (Fe)MIL-101@SCFs. The flame-retarded composites of epoxy resin (EP) were fabricated with combination of (Fe)MIL-101@SCFs and ammonium polyphosphate (APP). The composites showed good flame retardancy, smoke suppression, and mechanical properties simultaneously. The main heat release rate peak of the flame-retarded composites was reduced and delayed evidently in comparison with pristine EP. The high amount of residual char with coherent and dense structure was formed owing to the catalytic char formation of (Fe)MIL-101 as well as the strengthening action of SCF. The improvement in mechanical properties of the flame-retarded composite was due to the reinforcement effects of (Fe)MIL-101@SCFs and its action of interfacial adjustment. This research solved the contradiction between the flame retardancy and mechanical properties of EP, and proposed a new method to prepare the mechanically reinforced and flame retardant EP.     

Preparation of phosphorus‐containing phenolic resin and its application in epoxy resin as a curing agent and flame retardant

For the sake of improving the flame retardancy of epoxy resin (EP), a novel phosphorus‐containing phenolic resin (PPR) synthesized in our group instead of conventional phenolic resin (PR) was used to cure EP in the present research. The curing processes and the corresponding crosslinking structure and mechanical performance were investigated by differential scanning calorimeter and dynamic mechanical thermal analysis. Because of the introduction of flame‐retarding elements including P and Si, PPR exhibited higher charring capacity in the condensed phase, which is helpful to construct a char layer of higher quality. Correspondingly, PPR‐cured EP displayed remarkably improved flame retardance as compared to conventional PR‐cured EP through the related evaluations including limiting oxygen index, vertical burning test, and microscale combustion colorimeter. As a multifunction agent, it is believable that PPR possesses potential commercial value to prepare flame‐retardant EP with high performance.     

六苯氧基环三磷腈的热解及其对环氧树脂的阻燃机理

采用极限氧指数仪和锥形量热仪测试了以六苯氧基环三磷腈(HPCP)阻燃环氧树脂的燃烧性能,结果显示,与纯环氧树脂相比,阻燃环氧树脂的极限氧指数值(LOI)明显提高、热释放速率峰值(pk-HRR)和总热释放量(THR)明显下降、环氧树脂的点燃时间提前以及分解速度加快.采用热失重(TGA)、热重红外联用(TGA-FTIR)、X射线光电子能谱(XPS)和热裂解气相色谱质谱联用(Py-GC/MS)研究了HPCP及其阻燃环氧树脂的热解路线和阻燃机理.结果表明,在阻燃环氧树脂过程中,一方面,HPCP分子中的苯氧基团首先解离并发生歧化反应,由此产生的苯氧基及其歧化产物的焠灭效应在环氧树脂中发挥气相阻燃作用,剩余的磷腈环和苯环基团会进一步裂解产生小分子碎片;另一方面,环氧树脂基体在HPCP的作用下提前分解,产生了基于双酚A结构的大分子碎片并在HPCP裂解产物作用下加速炭化,从而使更多的基体组分以残炭的形式被固定在凝聚相中,提高了阻燃环氧树脂的残炭产率,发挥了凝聚相阻燃作用.     

Thermal degradation and flame retardancy of epoxy resins containing intumescent flame retardant

Pentaerythritol diphosphonate melamine-urea-formaldehyde resin salt, a novel cheap macromolecular intumescent flame retardants (IFR), was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus characterized by IR. Epoxy resins (EP) were modified with IFR to get the flame retardant EP, whose flammability and burning behavior were characterized by UL 94 and limiting oxygen index (LOI). 25 mass% of IFR were doped into EP to get 27.2 of LOI and UL 94 V-0. The thermal properties of epoxy resins containing IFR were investigated with thermogravimetry (TG) and differential thermogravimetry (DTG). Activation energy for the decomposition of samples was obtained using Kissinger equation. The resultant data show that for EP containing IFR, compared with EP, IFR decreased mass loss, thermal stability and R _max, increased the char yield. The activation energy for the decomposition of EP is 230.4 kJ mol⁻¹ while it becomes 193.8 kJ mol⁻¹ for EP containing IFR, decreased by 36.6 kJ mol⁻¹, which shows that IFR can catalyze decomposition and carbonization of EP.     

A flame‐retardant phosphate and cyclotriphosphazene‐containing epoxy resin: Synthesis and properties

A novel flame‐retardant epoxy resin, (4‐diethoxyphosphoryloxyphenoxy)(4‐glycidoxyphenoxy)cyclotriphosphazene (PPCTP), was prepared by the reaction of epichlorohydrin with (4‐diethoxyphosphoryloxyphenoxy)(4‐hydroxyphenoxy)cyclotriphosphazene and was characterized by Fourier transform infrared, ³¹P NMR, and ¹H NMR analyses. The epoxy resin was further cured with diamine curing agents, 4,4′‐diaminodiphenylmethane (DDM), 4,4′‐diaminodiphenylsulfone (DDS), dicyanodiamide (DICY), and 3,4′‐oxydianiline (ODA), to obtain the corresponding epoxy polymers. The curing reactions of the PPCTP resin with the diamines were studied by differential scanning calorimetry. The reactivities of the four curing agents toward PPCTP were in the following order: DDM > ODA > DICY > DDS. In addition, the thermal properties of the cured epoxy polymers were studied by thermogravimetric analysis, and the flame retardancies were estimated by measurement of the limiting oxygen index (LOI). Compared to a corresponding Epon 828‐based epoxy polymer, the PPCTP‐based epoxy polymers showed lower weight‐loss temperatures, higher char yields, and higher LOI values, indicating that the epoxy resin prepared could be useful as a flame retardant. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 972–981, 2000     

Synthesis of CeO2‐loaded titania nanotubes and its effect on the flame retardant property of epoxy resin

A series of CeO₂‐loaded titania nanotubes (CeO₂‐TNTs) hybrid materials with different CeO₂ loadings were synthesized by co‐precipitation method and then incorporated into epoxy resin (EP) to prepare CeO₂‐TNTs flame‐retardant epoxy nanocomposites. Structure and morphology characterization indicated the successful synthesis of CeO₂‐TNTs. The effect of CeO₂‐TNTs with different CeO₂ loading capacity on the flame retardance of EP was compared and analyzed by the thermogravimetric analysis, Cone and Raman. The results showed that CeO₂ loading could increase the carbon residue of nanocomposites, reduce the peak heat release rate (PHRR) and total heat release (THR), and improve the fire safety of EP. The residual carbon content of EP/0.1CeO₂‐TNTs sample at 700°C reached 19.8% with the lowest degradation rate, and the PHRR and THR were reduced to 680 kW/m² and 32.9 MJ/m², respectively. Such a significant improvement in flame‐retardant properties for EP could be attributed to the protective effect of CeO₂‐TNTs.     

Activated carbon spheres (ACS)@SnO2@NiO with a 3D nanospherical structure and its synergistic effect with AHP on improving the flame retardancy of epoxy resin

A novel activated carbon spheres (ACS)@SnO₂@NiO hierarchical hybrid architecture was first synthesized and applied for enhancing the flame retardancy of epoxy (EP) resin via a cooperative effect. Herein, using activated carbon microspheres as the template, SnO₂ and NiO nanospheres were successively anchored to it by a sedimentation‐calcination strategy. The well‐designed ACS@SnO₂@NiO significantly enhanced the flame retardancy for consistency of EP composites, as demonstrated by thermogravimetric and cone calorimeter experiments. For instance, the incorporation of 2 wt% ACS@SnO2@NiO decreased by 15.5% maximum in the total smoke production, accompanying the higher graphitized char layer. In addition, the synergetic mechanism of flame retardancy between ACS@SnO₂@NiO and aluminum hypophosphite (AHP) was investigated. The obtained sample satisfied the UL‐94 V‐0 rating with a 5.0 wt% addition of AHP and ACS@SnO₂@NiO (the ratio of the mass fraction of AHP to ACS@SnO₂@NiO is 4.5:0.5). Notably, the incorporation of AHP and ACS@SnO₂@NiO resulted in a significant decrease in the fire hazard properties of EP resin; for instance, 4.5AHP‐0.5ACS@SnO₂@NiO/EP resulted in a maximum decrease of 32.4% in the total smoke production as compared with that of pure EP resin. It should be noted that the improved flame‐retardant performance for the EP composites is primarily attributed to the synergistic effect of ACS@SnO₂@NiO and AHP in promoting the formation of residual char in the condensed phase.     

Novel nanocomposites based on epoxy resin and modified magnesium hydroxide: Focus on flame retardancy and mechanical properties

In this work, a novel multifunctional organic‐inorganic hybrid flame agent (AM‐MEL) was prepared from magnesium hydroxide nanosheets decorated by nitrilotrimethylene triphosphonic acid and melamine. Then, an intrinsic flame‐retardant epoxy resin (EP) was prepared by covalently incorporating AM‐MEL nanoparticles. Meanwhile, ammonium polyphosphate (APP) was added into EP to form an intumescent flame retardant system with AM‐MEL. The chemical structure of AM‐MEL was characterized by Fourier transform infrared spectra, X‐ray photoelectron spectroscopy, and scanning electron microscopy. With the incorporation of 5 wt% AM‐MEL and 15 wt% APP, EP/AM‐MEL/APP could reach a limiting oxygen index value of 32.0% and achieve UL‐94 V‐0 rating, along with 88.0%, 70.0%, 81.5%, and 87.3% decrease in the peak heat release rate, total heat release, total smoke production, and the peak CO production rate, respectively, with respect to that of pure EP. The mechanisms of its flame retardant and smoke suppression were investigated.     

Synthesis of DOPO‐based pyrazine derivative and its effect on flame retardancy and thermal stability of epoxy resin

A novel DOPO‐based pyrazine derivative 6‐((2‐hydroxyphenyl)(pyrazin‐2‐ylamino)methyl)dibenzo[c,e][1,2]oxaphosphinine 6‐oxide (DHBAP) was triumphantly synthesized by a two‐step addition reaction using 2‐aminopyrazine, 2‐hydroxybenzaldehyde and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) as reactants, and characterized by Fourier‐transform infrared (FTIR), ³¹P nuclear magnetic resonance (NMR) and ¹H NMR. Afterwards, the addition type flame retardant (DHBAP) was utilized to modify epoxy resin (EP) by blending method. When the content of DHBAP in neat EP was 8 wt%, it reached to the V‐0 rating and the limited oxygen index (LOI) value up to 34.0%. Furthermore, according to the cone calorimeter (CC) test results, the heat release rate (HRR), total heat release (THR), smoke produce rate (SPR) and total smoke production (TSP) of EP/8% DHBAP decreased by 26.3%, 21.3%, 37.0% and 60.9% when compared with neat EP, respectively, indicating that DHBAP had good inhibition on heat and smoke releases. Eventually, the flame‐retardant mechanism of DHBAP was further explored by X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy, and pyrolysis‐gas chromatography/mass spectrometry (Py‐GC/MS). The results showed that DHBAP had good flame‐retardant activity in the gasous‐condensed two phases.     

Synthesis of a caged bicyclic phosphates derived anhydride and its performance as a flame‐retardant curing agent for epoxy resins

A novel curing and flame‐retardant agent (PEPA‐TMAC) was successfully synthesized. The chemical structure was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Use of PEPA‐TMAC as part of the curing agent in combination with another anhydride for a commercial epoxy resin (EP) was studied. Results of differential scanning calorimetry (DSC) indicated that PEPA‐TMAC was an effective curing agent for EP. The dynamic mechanical analysis (DMA) results showed that the glass transition temperature (T_g) and cross‐linking density (V_e) of EP composites exhibited an increase trend with the addition of PEPA‐TMAC. The limiting oxygen index (LOI) value of EP composites reached 26.9%, and the cone calorimeter results indicated that peak heat release rate (PHRR), total heat release (THR), smoke produce rate (SPR), and total smoke produce (TSP) remarkably decreased with increasing PEPA‐TMAC content. TGA data showed that the addition of PEPA‐TMAC greatly increased the amount of residual char during combustion. The morphology of the residual char was studied by SEM and showed that the addition of PEPA‐TMAC greatly increased the stability of EP composites. The thermogravimetric analysis (TGA), energy‐dispersive X‐ray spectroscopy (EDS), and FTIR results revealed the flame‐retardant mechanism that PEPA‐TMAC can promote the formation of charred layers with the phospho‐carbonaceous complexes in the condensed phase during burning of EP composites.     

Polyphosphazene microspheres modified with transition metal hydroxystannate for enhancing the flame retardancy of polyethylene terephthalate

A novel PZS@CS hybrid structure was synthesized for enhancing the flame retardancy of polyethylene terephthalate (PET). The PZS@CS hybrids showed significant flame retardance. For example, the incorporation of 6 wt% PZS@CS obviously brought about an 8.8% increase of limiting oxygen index value (29.3%) and passed the vertical burning test UL‐94 V‐0 level, accompanied with the sharp reduction of heat and smoke release. The flame retardant mechanism of PZS@CS hybrids was fully studied by the Thermogravimetric Analysis (TGA), pyrolysis‐gas chromatography‐mass spectrometry, and Raman methods, and the results showed that the improvement of flame retardancy was mainly ascribed to the synergistic effect of PZS and CS phases in both the condensed and the gas phase. Rheological results showed that PZS@CS hybrids improved the melt complex viscosity of PET composites and the well compatibility of PET matrix and PZS@CS hybrids was also proved by the improvement of mechanical properties.     

Flame‐retardant epoxy resin compounds containing novolac derivatives with aromatic compounds

New flame‐retardant epoxy resin compounds containing novolac derivatives with specific aromatic compounds have been developed. After crosslinking reactions between epoxy resin and hardener, the epoxy resin compounds formed highly flame‐retardant network structures that were obtained by including biphenylene and phenylene moieties in the main chains of novolac‐type epoxy resin and phenol novolac resin hardener. The high flame retardancy is due mainly to the stable foam layers that form during combustion because of the low elasticity at high temperatures and the high pyrolysis resistance of the compounds. Furthermore, the addition of excess phenol derivative hardener not only facilitates the formation of the foam layers by decreasing the crosslink densities but also reduces the amount of flammable substances generated from the epoxy resin compounds during combustion. The use of a multifunctional epoxy resin containing four glycidyloxy groups in the compounds improved characteristics such as heat resistance and strength at high temperatures, while maintaining excellent flame retardancy. Copyright © 2001 John Wiley & Sons, Ltd.     

Synthesis of a novel phosphorus‐containing curing agent and its effects on the flame retardancy,thermal degradation and moisture resistance of epoxy resins

A novel phosphorus‐containing compound diphenyl‐(1, 2‐dicarboxylethyl)‐phosphine oxide defined as DPDCEPO was synthesized and used as a flame retardant curing agent for epoxy resins (EP). The chemical structure of the prepared DPDCEPO was well characterized by Fourier transform infrared spectroscopy, and ¹H, ¹³C and ³¹P nuclear magnetic resonance. The DPDCEPO was mixed with curing agent of phthalic anhydride (PA) with various weight ratios into epoxy resins to prepare flame retardant EP thermosets. The flame retardant properties, combustion behavior and thermal analysis of the EP thermosets were respectively investigated by limiting oxygen index (LOI), vertical burning tests (UL‐94), cone calorimeter measurement, dynamic mechanical thermal analysis and thermogravimetric analysis (TGA) tests. The surface morphologies and chemical compositions of the char residues for EP thermosets were respectively investigated by scanning electron microscopy and X‐ray photoelectron spectroscopy (XPS). The water resistant properties of the cured EP were evaluated by putting the samples into distilled water at 70°C for 168 hr. The results revealed that the EP/20 wt% DPDCEPO/80 wt% PA thermosets successfully passed UL‐94 V‐0 flammability rating and the LOI value was as high as 33.2%. The cone test results revealed that the incorporation of DPDCEPO effectively reduced the combustion parameters of the epoxy resin thermosets, such as heat release rate and total heat release. The dynamic mechanical thermal analysis test demonstrated that the glass transition temperature (Tg) decreased with the increase of DPDCEPO content. The TGA results indicated that the incorporation of DPDCEPO promoted the decomposition of epoxy resin matrix ahead of time and led to a higher char yield and thermal stability at high temperatures. The surface morphological structures and analysis of the XPS of the char residues of EP thermosets revealed that the introduction of DPDCEPO benefited the formation of a sufficient, compact and homogeneous char layer with rich flame retardant elements on the epoxy resin material surface during combustion. The mechanical properties and water resistance of the cured epoxy resins were also measured. After water resistance tests, the EP/20 wt% DPDCEPO/80 wt% PA thermosets retained excellent flame retardancy, and the moisture adsorption of the EP thermosets decreased with the increase of DPDCEPO content in EP thermosets because of the existence of the P–C bonds and the rigid aromatic hydrophobic structure in DPDCEPO. Copyright © 2015 John Wiley & Sons, Ltd.     

Highly efficient multielement flame retardant for multifunctional epoxy resin with satisfactory thermal,flame‐retardant,and mechanical properties

Multifunctional epoxy resins with excellent, thermal, flame‐retardant, and mechanical properties are extremely important for various applications. To solve this challenging problem, a novel highly efficient multielement flame retardant (PMSBA) is synthesized and the flame‐retardant and mechanical properties of modified epoxy resins are greatly enhanced without significantly altering their and thermal properties by applying the as‐synthesized PMSBA. The limiting oxygen index value reaches up to 29.6% and could pass the V‐0 rating in the UL‐94 test with even low P content (0.13%). Furthermore, cone calorimetry results demonstrate that 30.3% reduction in the peak heat release rate for the sample with 10.0 wt% PMSBA is achieved. X‐ray photoelectron spectroscopy and scanning electron microscopy indicate that Si‐C, Si‐N, and phosphoric acid derivative can be transformed into a multihole and intumescent char layer as an effective barrier, preserving the epoxy resin structure from fire. More importantly, mechanical properties such as impact strength, tensile strength, and flexural strength are also increased by 63.86%, 33.54%, and 15.65%, respectively, which show the incorporation of PMSBA do not deteriorate the mechanical properties of modified epoxy resins. All the results show that PMSBA is a promising strategy for epoxy resin with satisfactory, thermal, flame‐retardant, and mechanical properties.     

Preparation and characterization of microencapsulated LDHs with melamine‐formaldehyde resin and its flame retardant application in epoxy resin

Layered double hydroxides (LDHs) are emerging as a new and green high‐efficient flame retardant. But LDHs aggregate seriously because of their hydrophilicity, which affect deeply the mechanical and flame retardant properties of their composites. For the first time in this paper, microencapsulated LDHs (MCLDHs) with melamine‐formaldehyde (MF) resin were prepared by microencapsulation technology to enhance their compatibility and dispersion within epoxy resin (EP). The mechanical and flame retardant performances of EP/MCLDH composite were studied by comparing with EP/LDH composite. Results showed that the water contact angle of MCLDHs increased from 8.9° to 122.1°, which indicated good compatibility. The particle size of MCLDHs decreased sharply, and more than one‐third were up to submicron scale, which can be conducive to dispersion. Moreover, the tensile strength and elongation at break of EP/MCLDHs with different flame retardant contents were higher than those of EP/LDHs. And the addition of MCLDHs increased the glass transition temperature (Tg) of EP/MCLDHs, which meant a strong interfacial interaction. Besides, compared with EP/LDHs, the limiting oxygen index values of EP/MCLDHs were higher, and its peak of heat release rate and total heat release decreased by 16.3% and 5.5% respectively. EP/MCLDHs achieved from V‐1 to V‐0 rate with the increasing content of MCLDHs from 20% to 30%, while LDHs/EP never passed tests. In the process of heating, H₂O, CO₂, and NH₃ released from MCLDHs formed gaseous phase, and the remaining dense char layers and oxides produced condensed phase, which played an important role in inhibiting combustion.     

The effect of a novel phosphorus-nitrogen reactive flame retardant curing agent on the performance of epoxy resin

A phosphorus-nitrogen reactive flame retardant curing agent poly-(isophorondiamine spirocyclic pentaerythritol bisphosphonate) (PIPSPB) was synthesized. The chemical structure of the obtained compound was identified by FTIR, ¹HNMR, and mass spectroscopies. Different proportions of DDS and PIPSPB were compounded as the curing agents to prepare a series of flame retardant epoxy resins with different phosphorus contents. The curing behavior of E-44/PIPSPB?+?DDS system was studied by DSC. A series of tests were conducted to characterize E-44/PIPSPB?+?DDS thermosetting system’s performance. The result demonstrates that the residual carbon content of EP/PIPSPB?+?DDS system is obviously higher than that of EP/DDS system after 500?°C with the increase of phosphorus content in the system, and the heat release rate of the system during combustion is significantly reduced. The generated phosphorus-containing carbon layer is obviously foamed, which shows that the flame retardancy of the system is the result of the combined action of condensed phase and gas phase. When the phosphorus content is 1.77wt%, EP-3 successfully passed UL94 V-0 flammability rating, the LOI value was as high as 29%, the impact strength and tensile strength of it were 6.08KJ/m² and 49.10MPa respectively, the adhesive strength could reach 13.89?MPa, the system presents a good overall performance.     

Synthesis and characterization of P/Si flame retardant and its application in epoxy systems

In this report, a novel phosphorus/silicon‐containing reactive flame retardant, hexa(3‐triglycidyloxysilylpropyl)triphosphazene (HGPP), was synthesized and characterized by Fourier transform infrared spectrometry and nuclear magnetic resonance spectra (¹H, ³¹P, and ²⁹Si), respectively. To prepare cured epoxy, HGPP had been co‐cured with diglycidyl ether of bisphenol‐A (DGEBA) via 4,4‐diaminodiphenylsulfone as a curing agent. The mechanical, thermal, and flame retardant properties of the cured epoxy were evaluated by dynamic mechanical analysis, thermogravimetric analysis, and limiting oxygen index (LOI). According to these results, it could be found that incorporation of HGPP in the cured epoxy system showed good thermal stability, high LOI values, and high char yield at high temperature. As moderate loading of HGPP in the epoxy system, its storage modulus and glass transition temperature were higher than those of neat DGEBA. Copyright © 2011 John Wiley & Sons, Ltd.