FIRE PROTECTIVE EFFICIENCY OF INTUMESCENT TYPE EPOXIDE COATING

2021 ◽  
pp. 143-153
Author(s):  
Lyubov Vakhitova ◽  
◽  
Nadiya Taran ◽  
Konstantin Kalafat ◽  
Volodymyr Bessarabov ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Epoxy Resins ◽  
Flame Retardants ◽  
Practical Importance ◽  
Fire Retardant ◽  
Practical Significance ◽  
Protective Efficiency ◽  
Intumescent Coating ◽  
Polymer Component ◽  
Intumescent System

Purpose. The purpose of this work is to study the thermal degradation of epoxy polymers and nanocomposites based on them in a fire retardant intumescent coating having a composition – ammonium polyphosphate / melamine / pentaerythritol. Methods. Thermogravimetric studies have been performed on the device “Thermoscan-2”, fire tests were performed by the method of “Bunsen burner”. Results. The influence of the structure of epoxy resin as a polymer component of the intumescent system on oxidative thermal destruction and fire retardant efficiency of reactive coating has been researched. The obtained results allow us to state that the best result has been demonstrated by Araldite GY 783 – epoxy resin of bisphenols A/F with a reactive solvent. The thermal properties of various epoxy resins and nanocomposites based on them with organomodified montmorillonite have been studied. It was found that montmorillonite in the nanocomposite increases the decomposition temperature of epoxy resin. Scientific novelty. It has been shown that the variation of the polymer component of the intumescent coating has little effect on the swelling rate, but the fire retardant efficiency of the intumescent composition containing epoxy resin of bisphenols A/F is higher than the same characteristic for the composition based on epoxy resin of bisphenol A. It has been established that the exclusion of pentaerythritol from the formulation of the epoxy intumescent system causes the formation of a more regular and durable char insulation layer. It has been proved that the use of additional, including nanostructured flame retardants, namely, modified montmorillonite, can increase the fire retardant efficiency of the coating. Practical significance. The obtained results are of practical importance for the development of new scientific approaches to the design of fire-fighting materials with improved performance characteristics through the use of polymers that provide the construction of a thermostable thermal insulation char layer. Through a series of systematic tests, it has been demonstrated that the use of nanoclay and nanocomposites based on epoxy resins allows to improve the formulations of intumescent coatings with high performance with the help of budget nanotechnologies.

TRENDS IN THE DEVELOPMENT OF REACTIVE FIRE PROTECTION (LITERATURE REVIEW)

2021 ◽  
pp. 75-90
Author(s):  
Lyubov Vakhitova ◽  
◽  
Nadiya Taran ◽  
Konstantin Kalafat ◽  
◽  
...  
Keyword(s):  
Literature Review ◽  
Fire Protection ◽  
Flame Retardants ◽  
Practical Importance ◽  
Fire Retardant ◽  
Steel Structures ◽  
Life Time ◽  
Practical Significance ◽  
Protection Measures ◽  
The Cost

Purpose. Identification of the main directions of evolution of scientific researches concerning development and improvement of fire protective reactive coatings of intumescent type for steel constructions. Methods. Analysis of literature sources, study and generalization of information, classification and modeling of chemical processes. Results. As a result of the performed researches it has been shown that of all the developed reactive fire protection systems for increasing the fire resistance of steel structures the intumescent composition of ammonium polyphosphate/ pentaerythritol / melamine / polymer is the most widespread and economically justified. To reduce the cost of fire protection measures, it is necessary to improve the coatings of the intumescent type in the following main areas: increasing of fire protection efficiency with a decrease in the thickness of the fire protection layer; prolongation of life time with strengthening of resistance to external factors; reducing the cost of the prescription composition of intumescent paint due to the use of nanomaterials. Scientific novelty. It has been established that nanoclays, nanooxides of metals and silicon, LDH compounds and their analogues should be considered the most promising and multifunctional. The presence of nanomaterials in intumescent compositions allows to increase the environmental parameters of fire-retardant treatment due to the rejection of halogen flame retardants, boron compounds, formaldehyde resins. In addition, the presence of nanocompounds in intumescent coatings significantly reduces smoke in fire. Practical significance. The conclusions obtained from the literature review are of practical importance for the development of new approaches to the design of fire-fighting materials with improved performance through the use of nanomaterials, which provides a strong fire retardant foam char layer and provides rigidity of the insulation frame.

scholarly journals ПІДВИЩЕННЯ ВОГНЕЗАХИСНОЇ ЕФЕКТИВНОСТІ ІНТУМЕСЦЕНТНИХ ЕПОКСИДНИХ ПОКРИТТІВ СПОЛУКАМИ ІНТЕРКАЛЬОВАНОГО ГРАФІТУ

2021 ◽  
Vol 152 (6) ◽  
pp. 55-65
Author(s):  
Л. М. Вахітова ◽  
В. П. Плаван ◽  
В. І. Шологон ◽  
К. В. Калафат ◽  
Н. А. Таран ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Oxidative Degradation ◽  
Fire Retardant ◽  
Ammonium Polyphosphate ◽  
Thermal Oxidative Degradation ◽  
Char Residue ◽  
Temperature Range ◽  
Char Layer ◽  
Polymer Component ◽  
Intumescent System

Investigation of the effect of nitrate oxide graphite on the parameters of char layer, obtained from the system of ammonium polyphosphate / melamine / pentaerythritol / epoxy resin under the influence of temperatures of 200–800 °С.  Methodology.  A  fire  retardant  mixture  was  chosen  as  a  model  intumescent  system  ammonium polyphosphate / melamine / pentaerythritol. As a polymer component was used bisphenols A / F epoxy resin together with a polyamidoamine hardener. Nitrate oxide graphite was obtained by oxidation of natural scaly graphite  with fuming  nitrogen  acid.  The  effect  of  impurities  of  nitrate  oxide  graphite  was  determined  by thermogravimetry  on  the  intumescence  coefficient  of  intumescent  compositions  and  the  mass  of  the  char residue intumescent compositions in temperature range of 200–800 °С.  Findings. The influence of nitrate oxide graphite on the characteristics was studied of char layer of epoxy intumescent system ammonium polyphosphate / melamine / pentaerythritol / epoxy resin. The study of thermal  oxidative  degradation  was  carried  out  intumescent  compositions  in  the  temperature  range  200–800 °С. It was shown that intercalated graphite compounds increase the thermal stability of the formed char layer at temperatures > 600 °С. Determined intumescence coefficients and thermogravimetric analysis of modified intumescent systems was performed nitrate oxide graphite with different degrees of intercalation, in the conditions of 200–800 °С. It was established that the optimal parameters of the char layer are in terms of volume intumescence coefficient and mass of the char residue are provided by graphites, which contain 15–25% of intercalant in its composition. But the results obtained allow us to determine nitrate oxide graphite as a promising modifier of epoxy intumescent systems to increase its fire protection efficiency. Originality.  The  influence  of  degree  of  intercalation  of  nitrate  oxide  graphite  was  studied  on  the characteristics of char layer of epoxy intumescent system for the first time.  Practical value. The optimal content of intercalant in nitrate oxide graphite was established for the development of formulations of intumescent epoxy coatings with increased fire retardant properties.

scholarly journals Bioinspired iron-loaded polydopamine nanospheres as green flame retardants for epoxy resin via free radical scavenging and catalytic charring

2020 ◽  
Vol 8 (5) ◽  
pp. 2529-2538 ◽  
Author(s):  
Lu Zhang ◽  
Qi Wang ◽  
Rong-Kun Jian ◽  
De-Yi Wang
Keyword(s):  
Free Radical ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Flame Retardants ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Highly Efficient

Iron-loaded polydopamine nanospheres act as nontoxic and highly efficient flame retardants in epoxy resins via free radical scavenging and catalytic charring actions.

scholarly journals New Biosourced Flame Retardant Agents Based on Gallic and Ellagic Acids for Epoxy Resins

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4305 ◽  
Author(s):  
Valeriia Karaseva ◽  
Anne Bergeret ◽  
Clément Lacoste ◽  
Hélène Fulcrand ◽  
Laurent Ferry
Keyword(s):  
Phenolic Compounds ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Flame Retardants ◽  
Fire Behavior ◽  
Diglycidyl Ether ◽  
Scanning Calorimetry ◽  
Burning Behavior ◽  
Borate Ester ◽  
Thermal Stability Of

The aim of this work was an investigation of the ability of gallic (GA) and ellagic (EA) acids, which are phenolic compounds encountered in various plants, to act as flame retardants (FRs) for epoxy resins. In order to improve their fireproofing properties, GA and EA were treated with boric acid (to obtain gallic acid derivatives (GAD) and ellagic acid derivatives (EAD)) to introduce borate ester moieties. Thermogravimetric analysis (TGA) highlighted the good charring ability of GA and EA, which was enhanced by boration. The grafting of borate groups was also shown to increase the thermal stability of GA and EA that goes up respectively from 269 to 528 °C and from 496 to 628 °C. The phenolic-based components were then incorporated into an epoxy resin formulated from diglycidyl ether of bisphenol A (DGEBA) and isophorone diamine (IPDA) (72, 18, and 10 wt.% of DGEBA, IPDA, and GA or EA, respectively). According to differential scanning calorimetry (DSC), the glass transition temperature (Tg) of the thermosets was decreased. Its values ranged from 137 up to 108 °C after adding the phenolic-based components. A cone calorimeter was used to evaluate the burning behavior of the formulated thermosets. A significant reduction of the peak of heat release rate (pHRR) for combustion was detected. Indeed, with 10 wt.% of GA and EA, pHRR was reduced by 12 and 44%, respectively, compared to that for neat epoxy resin. GAD and EAD also induced the decrease of pHRR values by 65 and 33%, respectively. In addition, a barrier effect was observed for the resin containing GAD. These results show the important influence of the biobased phenolic compounds and their boron derivatives on the fire behavior of a partially biobased epoxy resin.

scholarly journals ПОРІВНЯННЯ ПОЛІОЛІВ ЯК КАРБОНІЗУЮЧИХ АГЕНТІВ ВОГНЕЗАХИСНИХ КОМПОЗИЦІЙ ІНТУМЕСЦЕНТНОГО ТИПУ

2022 ◽  
pp. 27-36
Author(s):  
LIUBOV VAKHITOVA ◽  
KONSTANTIN KALAFAT ◽  
NADIYA TARAN ◽  
VOLODYMYR BESSARABOV
Keyword(s):  
High Temperatures ◽  
Fire Protection ◽  
Flame Retardants ◽  
Fire Retardant ◽  
Reaction Products ◽  
Protection Efficiency ◽  
Char Layer ◽  
Thermal Insulating ◽  
Intumescent Coatings ◽  
Intumescent System

Purpose. To study the influence of the carbonizing agent structure on the formation of thermal insulating char layer of intumescent system acid donor/polyol and on the fire protection efficiency of the system at high temperatures. Methodology. A fire retardant mixture of an acid donor (phosphates ammonium, urea, melamine)/ polyol was chosen as a model intumescent system. Dispersion of vinyl acetate copolymer with ethylene was used as a polymeric component. The study applied the characteristics of the char layer of the intumescent composition at a certain temperature. The volumetric intumescent coefficient (K, cm3/g), mass of char residue (m, %), structure and density of the char layer are proposed as the main estimated parameters of flame retardant effect. IR spectroscopy was used to identify products of thermolysis of intumescent systems. Determination of fire protection efficiency of intumescent coatings was carried out in a mini-oven under standard fire conditions. Findings. The influence of polyol structure on the formation of thermal insulating char layer of intumescent acid donor/polyol system and the prediction of fire protection efficiency of this system under high temperature conditions has been investigated. It has been shown that under conditions of thermal shock the fire protection efficiency is more dependent on the nucleophilic reactivity of the polyol towards the unsaturated phosphorus atom of the acid donor than on its thermal stability. It has been found that pentaerythritol, dipentaerythritol, starch, dextrin, xylitol and sorbitol are the most effective carbonizing agents, regardless of the structure of the acid donor. It has been proved by infrared spectroscopy that at high temperatures as a result of the decomposition of pentaerythritol one of the reaction products is the aldehydes interacting with pentaerythritol with the formation of oligomeric compounds with a simple ether bond C-O-C. At the same time, pentaerythritol can be considered as a universal source of carbon framework for intumescent flame retardants regardless of the phosphate structure used. Originality. It has been shown that an important factor to increase the fire protection efficiency of intumescent systems is the use of polyols with an increased nucleophilicity in the esterification between polyol and phosphoric acid.Practical value. The optimal polyols as carbonizing agents for formulation of intumescent coatings with enhanced fire protection properties have been determined.

Epoxy Resin Embedment

1968 ◽  
Vol 26 ◽  
pp. 100-101
Author(s):  
J. G. Adams ◽  
M. M. Campbell ◽  
H. Thomas ◽  
J. J. Ghldonl
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Epoxy Resin ◽  
Light Microscope ◽  
Epoxy Resins ◽  
Image Contrast ◽  
Tissue Preservation ◽  
Resin System ◽  
Excellent Quality

Since the introduction of epoxy resins as embedding material for electron microscopy, the list of new formulations and variations of widely accepted mixtures has grown rapidly. Described here is a resin system utilizing Maraglas 655, Dow D.E.R. 732, DDSA, and BDMA, which is a variation of the mixtures of Lockwood and Erlandson. In the development of the mixture, the Maraglas and the Dow resins were tested in 3 different volumetric proportions, 6:4, 7:3, and 8:2. Cutting qualities and characteristics of stability in the electron beam and image contrast were evaluated for these epoxy mixtures with anhydride (DDSA) to epoxy ratios of 0.4, 0.55, and 0.7. Each mixture was polymerized overnight at 60°C with 2% and 3% BDMA.Although the differences among the test resins were slight in terms of cutting ease, general tissue preservation, and stability in the beam, the 7:3 Maraglas to D.E.R. 732 ratio at an anhydride to epoxy ratio of 0.55 polymerized with 3% BDMA proved to be most consistent. The resulting plastic is relatively hard and somewhat brittle which necessitates trimming and facing the block slowly and cautiously to avoid chipping. Sections up to about 2 microns in thickness can be cut and stained with any of several light microscope stains and excellent quality light photomicrographs can be taken of such sections (Fig. 1).

The Mechanical Properties of Organic Modified Epoxy Resin

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.

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.

scholarly journals Chlorine-Functional Silsesquioxanes (POSS-Cl) as Effective Flame Retardants and Reinforcing Additives for Rigid Polyurethane Foams

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3979
Author(s):  
Anna Strąkowska ◽  
Sylwia Członka ◽  
Karolina Miedzińska ◽  
Krzysztof Strzelec
Keyword(s):  
Flame Retardants ◽  
Elevated Temperatures ◽  
Bending Strength ◽  
Reaction System ◽  
Fire Retardant ◽  
Polyurethane Foams ◽  
Polymerization Reaction ◽  
Three Point Bending ◽  
One Step

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.

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