Investigation on the Flame Retardant Properties and Fracture Toughness of DOPO and Nano-SiO2 Modified Epoxy Novolac Resin and Evaluation of Its Combinational Effects

In this study, the flame-retardant, thermal and mechanical properties of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and nano-SiO2 modified epoxy novolac resin is evaluated, and the combinational effects of both additives are verified. As a hardener, an isophorone diamine (IPDA) and polyetheramine blend is stoichiometrically added to obtain a low viscous epoxy resin system, suitable for resin injection and infusion techniques. The glass transition temperature (Tg) and the silica dispersion quality is affected by the DOPO modification and the nano silica particles. The flame-retardant (FR) and mechanical properties of the additives are investigated separately. The fracture toughness could be increased with the incorporation of both FR additives; however, the effect is deteriorated for higher DOPO amount which is referred to silica particle agglomeration and consequently reduced shear yielding mechanism. Flame-retardant properties, especially the peak heat release rate (pHRR) and the total heat release (THR) could be decreased from 1373.0 kW/m2 of neat novolac to 646.6 kW/m2 measured by resins with varying phosphorous and silica content. Thermogravimetric analysis (TGA) measurements show the formation of a high temperature stable char layer above 800 °C which is attributed to both additives. Scanning electron microscopy (SEM) images are taken to get deeper information of the flame-retardant mechanism, showing a dense and stable char layer for a certain DOPO silica mixture which restrains the combustible gases from the burning zone in the cone calorimeter test and influences the fire behavior of the epoxy resin.

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Effects of a Macromolecule Spirocyclic Inflatable Flame Retardant on the Thermal and Flame Retardant Properties of Epoxy Resin

Polymers ◽

10.3390/polym12010132 ◽

2020 ◽

Vol 12 (1) ◽

pp. 132 ◽

Cited By ~ 3

Author(s):

Kunpeng Song ◽

Yinjie Wang ◽

Fang Ruan ◽

Jiping Liu ◽

Nianhua Li ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Epoxy Resin ◽

Phosphorus Oxychloride ◽

Raw Materials ◽

Smoke Suppression ◽

Step Method ◽

Scanning Calorimetry ◽

New Strategy ◽

Flame Retardant Properties

A new strategy for the preparation of an integrated three-source intumescent flame retardant (IFR) has been developed to improve the flame-retardant and smoke suppression performance of epoxy resin (EP) with a synergistic flame retardant effect. Herein, the synthesis of a macromolecular spirocyclic phosphorus/nitrogen-containing IFR poly sulfonamide spirocyclic pentaerythritol bisphosphonate (SAPC) is reported via a two-step method that uses pentaerythritol, phosphorus oxychloride and sulfonamide (SAA) as raw materials. Subsequently, the SAPC was incorporated into EP to prepare the composite to investigate its thermal stability, flame retardancy, and smoke suppression performance. Herein, a differential scanning calorimetry (DSC) analysis showed that the addition of SAPC increased the glass transition temperature (Tg) of the composite. Cone test results indicated that the incorporation of 8 wt % SAPC significantly improved the flame-retardant performance for the composite, with a 43.45% decrease in peak of heat release rate, a 28.55% reduction in total heat release, and a 30.04% decrease in total smoke release. Additionally, the composite received the V-0 rating in a UL-94 vertical burning test, accompanied by the “blowout” phenomenon. After the addition of SAPC, the amount of flammable gas products from the EP composite decomposition was obviously suppressed, and the amount of non-flammable as was increased. All of this suggests a good dilution role of SAPC. There are enough reasons to believe that the enhanced flame-retardant and toxicity suppression performance for the EP composite can be attributed to the good coordination of carbonization agent, acid source, and blowing agent in the SAPC structure.

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Evaluation of DOPO and Nano-Silica Modified Epoxy Resin Systems as Low Viscous, Flame Retardant Additives for Infusion and Injection Processing of Carbon Fiber Reinforced Plastics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.809.3 ◽

2019 ◽

Vol 809 ◽

pp. 3-8

Author(s):

Markus Häublein ◽

Karin Peter ◽

Alexander Brückner ◽

Volker Altstädt

Keyword(s):

Carbon Fiber ◽

Flame Retardant ◽

Epoxy Resin ◽

Volume Content ◽

Cone Calorimeter ◽

Fiber Reinforced ◽

Fiber Volume ◽

Carbon Fiber Reinforced ◽

Flame Retardant Properties ◽

Modified Epoxy

In the present study, a low viscous (complex viscosity between 200 to 500 mPas at 60 °C), flame retardant epoxy resin formulation is prepared and transferred to the carbon fiber reinforced plastic (CFRP) laminate using resin transfer molding (RTM) method. For the laminate production, a 12k carbon fiber fabric with an areal weight of 400 g/m2 is used to achieve a fiber volume content of approximately 60 vol % carbon fibers. Subsequently the unmodified laminate is produced, varying carbon fiber volume content to study its effect on flame retardant properties. As additives, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) modified epoxy resin and nanosilica particles delivered in an epoxy novolac masterbatch are added to the neat novolac resin system. The mixture is cured with isophorone diamine (IPDA) and polyetheramine hardener blend, resulting in a glass transition temperature of 104 °C for the unmodified laminate. Flame retardant properties of the materials are tested using cone calorimeter and thermal gravimetrical analysis. In addition, the mechanical behavior of the systems is evaluated via three-point bending method in static and dynamical loadings. In order to get deeper information on the resulting flame retardant mechanisms of the additives, the residual cone calorimeter char is analyzed with scanning electron microscopy, indicating the different flame retardant mechanisms of phosphorous and silica as well as the combination of both additives.

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Hybrid Biocomposites Based on Used Coffee Grounds and Epoxy Resin: Mechanical Properties and Fire Resistance

International Journal of Chemical Engineering ◽

10.1155/2021/1919344 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Tuan Anh Nguyen ◽

Quang Tung Nguyen

Keyword(s):

Mechanical Properties ◽

Flame Retardant ◽

Epoxy Resin ◽

Oxygen Index ◽

Low Cost ◽

Sem Images ◽

Coffee Grounds ◽

Wide Range ◽

Sustainable Materials ◽

Flame Retardant Properties

Studies on using biomaterials hybridized with other materials to produce biomaterials have been paid more attention due to their low cost, abundance, renewability, and degradability. Therefore, these materials are ecofriendly and nontoxic to humans. A large number of used coffee grounds (SCGs) are often discarded and replacements are necessary for dealing with environmental problems. This work developed sustainable materials by reusing SCGs. Used coffee grounds were mixed with epoxy resin at different amounts: 30 wt %, 40 wt %, 50 wt %, and 60 wt %. SCGs were treated with 0.5 N NaOH, at SCGs/NaOH ratio of 1 : 2. SEM images showed that the material with 30 wt % SCGs has good compatibility without phase division on the SCGs-epoxy interface. Results of mechanical properties of epoxy composites with 30 wt % SCGs are as follows: tensile strength of 44.81 ± 10 MPa, flexural strength of 80.07 ± 0.16 MPa, compressive strength of 112.56 ± 0.11 MPa, and Izod strength and impact of 8.21 ± 0.19 kJ/m2. In terms of flame-retardant properties, the oxygen index is limited to 20.8% ± 0.20 and the burning rate according to UL94HB is 27.02 ± 0.29 mm/min. The obtained results indicate that it is possible to produce biohybrid composites from epoxy resin and SCGs. This work offers an ecofriendly alternative method to use the waste of the coffee industry. It contributes to improvements of the general characteristics of composites such as mechanical, thermal, and flame-retardant properties. This work proved that SCGs have a high potential to be used in a wide range of composite materials for civil engineering applications.

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Rigid Polyurethane Foams Containing Modified Ammonium Polyphosphate Having Outstanding Charring Ability and Increased Flame Retardancy

Frontiers in Materials ◽

10.3389/fmats.2021.712809 ◽

2021 ◽

Vol 8 ◽

Author(s):

Chunzhuang Yang ◽

Shuiyu Shao

Keyword(s):

Mechanical Properties ◽

Heat Release ◽

Flame Retardant ◽

Degree Of Polymerization ◽

Polyurethane Foams ◽

Ammonium Polyphosphate ◽

Cone Calorimeter Test ◽

Compressive Strength Test ◽

Flame Retardant Properties ◽

The Impact

Ammonium polyphosphate (APP) with different polymerization degrees were modified by a novel phosphorus-containing organosilicon compound (PCOC), and the products obtained were coded as MAPP-30 and MAPP-1000. Then they were applied to prepare flame-retardant rigid polyurethane foam (RPUF) separately. The impact of modified APP (MAPP) on the flame-retardant properties of RPUF was investigated by the limited oxygen index (LOI) test, horizontal burning test, and cone calorimeter test. The morphologies of the char residues were observed by SEM. Furthermore, the mechanical properties of RPUF composites were measured by the compressive strength test. The results showed that whether the degree of polymerization of MAPP is 30 or 1000, they both had greater charring ability and better flame-retardant properties than unmodified APP. The residual char yield of RPUF/MAPP-30 (37.3%) and RPUF/MAPP-1000 (36.5%) were both significantly higher than RPUF/APP-30 (22.8%) and RPUF/APP-1000 (24.9%). The peak heat release rate value of RPUF/MAPP-30 was 29.9% lower than that of RPUF/APP-30, and the drop of RPUF/MAPP-1000 was 50.9% compared to RPUF/APP-1000. Moreover, the total heat release of RPUF/MAPP-1000 (9.7 MJ/m2) was much lower than that of RPUF/MAPP-30 (11.3 MJ/m2). In summary, MAPP-1000 has the best flame-retardant properties among all RPUF composites. In addition, the results also showed that flame-retardant performance and the mechanical properties dramatically decreased with the increase in the addition of MAPP-1000, and the RPUF composite had the best comprehensive performance with 20% content of MAPP-1000.

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The Mechanical Properties of Organic Modified Epoxy Resin

The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science ◽

10.35219/mms.2020.3.02 ◽

2020 ◽

Vol 43 (3) ◽

pp. 10-14

Author(s):

Georgel MIHU ◽

Claudia Veronica UNGUREANU ◽

Vasile BRIA ◽

Marina BUNEA ◽

Rodica CHIHAI PEȚU ◽

...

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Epoxy Resin ◽

Epoxy Matrix ◽

Epoxy Resins ◽

Mechanical Tests ◽

Organic Modification ◽

Three Point Bending ◽

Modified Epoxy

Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.

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Dual UV-Thermal Curing of Biobased Resorcinol Epoxy Resin-Diatomite Composites with Improved Acoustic Performance and Attractive Flame Retardancy Behavior

Sustainable Chemistry ◽

10.3390/suschem2010003 ◽

2021 ◽

Vol 2 (1) ◽

pp. 24-48

Author(s):

Quoc-Bao Nguyen ◽

Henri Vahabi ◽

Agustín Rios de Anda ◽

Davy-Louis Versace ◽

Valérie Langlois ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

Sound Absorption ◽

Flexural Modulus ◽

Construction Materials ◽

Acoustic Properties ◽

Low Frequencies ◽

Compacting Pressure

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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SEBS-based thermoplastic elastomers containing aluminum hypophosphite and melamine cyanurate: Thermal degradation, flame retardancy, and mechanical properties

Journal of Fire Sciences ◽

10.1177/0734904119830591 ◽

2019 ◽

Vol 37 (2) ◽

pp. 137-154 ◽

Cited By ~ 1

Author(s):

Xi Cheng ◽

Jianming Wu ◽

Yulin Li ◽

Chenguang Yao ◽

Guisheng Yang

Keyword(s):

Flame Retardant ◽

Thermoplastic Elastomers ◽

Char Residue ◽

Melamine Cyanurate ◽

Char Layer ◽

Phenylene Oxide ◽

Peak Heat Release Rate ◽

Ul 94 ◽

Flame Retardant Properties ◽

Aluminum Hypophosphite

Aluminum hypophosphite combined with melamine cyanurate and poly(phenylene oxide) was applied to flame-retard TPE-S system (blends of SEBS and polyolefin). The flame-retardant properties of the TPE-S/AHP/MCA/PPO were investigated by LOI and vertical burning test (UL-94). The results indicated that TPE-S containing 16 wt% AHP, 20 wt% MCA, and 10 wt% PPO reached a V-0 rating in the UL-94 test, and its LOI value was 28.2%. It performed well in the cone calorimeter (reduction in peak heat release rate from 2001 to 494 kW m−2). Thermogravimetric-Fourier transform infrared spectroscopy tests showed that AHP and MCA acted in gaseous phase, while AHP and PPO helped to form char residue. The SEM graphs demonstrated that continuous and compact films cover bubbles of the char layer in TPE-S/AHP/MCA/PPO. The proposed flame-retardant mechanisms of such systems were summarized.

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Thermal Stabilities and the Thermal Degradation Kinetics Study of the Flame Retardant Epoxy Resins

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1053.263 ◽

2014 ◽

Vol 1053 ◽

pp. 263-267 ◽

Cited By ~ 1

Author(s):

Xiu Juan Tian

Keyword(s):

Thermal Stability ◽

Thermal Degradation ◽

Flame Retardant ◽

Epoxy Resin ◽

Epoxy Resins ◽

Degradation Kinetics ◽

Thermal Degradation Kinetics ◽

Thermal Stabilities ◽

Degradation Kinetic ◽

Modified Epoxy

Thermal stability and thermal degradation kinetics of epoxy resins with 2-(Diphenylphosphinyl)-1, 4-benzenediol were investegated by thermogravimetric analysis (TGA) at different heating rates of 5 K/min, 10 K/min, 20 K/min and 40 K/min. The thermal degradation kinetic mechanism and models of the modified epoxy resins were determined by Coast Redfern method.The results showed that epoxy resins modified with the flame retardant had more thermal stability than pure epoxy resin. The solid-state decomposition mechanism of epoxy resin and the modified epoxy resin corresponded to the controlled decelerating ځ˽̈́˰̵̳͂͆ͅ˼˰̴̱̾˰̸̵̈́˰̵̸̳̱̹̽̾̓̽˰̶̳̹̾̈́̿̾̓ͅ˰̶˸ځ˹˰̵̵͇͂˰̃˸́˽ځ˹2/3. The introduction of phosphorus-containing flame retardant reduced thermal degradation rate of epoxy resins in the primary stage, and promote the formation of carbon layer.

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Mechanichal Properties of DGEBA/TEPA Modified Epoxy Resin

Materials Science Forum ◽

10.4028/www.scientific.net/msf.775-776.588 ◽

2014 ◽

Vol 775-776 ◽

pp. 588-592

Author(s):

Camila Rodrigues Amaral ◽

Ruben Jesus Sanchez Rodriguez ◽

Magno Luiz Tavares Bessa ◽

Verônica Scarpini Cândido ◽

Sergio Neves Monteiro

Keyword(s):

Mechanical Properties ◽

Plastic Deformation ◽

Epoxy Resin ◽

Yield Stress ◽

Diglycidyl Ether ◽

Notch Toughness ◽

Epoxy Network ◽

Structural Network ◽

Flexural Tests ◽

Modified Epoxy

The correlation between the structural network of a diglycidyl ether of the bisphenol-A (DGEBA) epoxy resin, modified by two distinct aliphatic amines (tetraethylenepentamine TEPA and jeffamine D230), and its mechanical properties, was investigated as possible matrix for abrasive composites applications. Both flexural tests, to determine the yield stress and the elastic modulus, as well as impact tests to determine the notch toughness, were performed. The DGEBA/D230 presented the highest stiffness and toughness but lowest yield stress. This epoxy network also displayed a greater plastic deformation during fracture.

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