Investigation of the Effect of Fillers on the Properties of the Expanded Coke Layer of Epoxyamine Compositions

2021 ◽  
Vol 1038 ◽  
pp. 539-546
Author(s):  
Oleksandr Hryhorenko ◽  
Yevheniia Zolkina ◽  
Natalia Vyacheslavovna Saienko ◽  
Yuri Viktorovich Popov
Keyword(s):  
Flame Retardant ◽  
Titanium Oxide ◽  
Aluminum Hydroxide ◽  
Experimental Studies ◽  
Fire Retardant ◽  
Ammonium Polyphosphate ◽  
Linear Coefficient ◽  
Epoxy Oligomers ◽  
Wide Range ◽  
Coke Layer

Intumescent fire-retardant coatings based on epoxy resins, compared to traditional fire-retardant compositions, have improved performance properties – high strength, chemical and atmospheric resistance, adhesion to many materials. However, unmodified epoxy polymers are combustible and to obtain IFR based on them, flame retardants and mineral fillers are added to their composition. Intumescent systems for flame retardant coatings based on epoxy oligomers (non-halogen-containing) usually consist of ammonium or ammophos polyphosphate as an acidic agent and a wide range of fillers, both inert and gaseous, or which are an additional source of carbon. Each component of the fire-retardant intimate coating in different ways affects the processes of coke formation, which determines the requirements for their choice. Thus, the aim of this work is to conduct experimental studies of the dependence of the characteristics of the expanded coke layer on the composition of the intumescent epoxyamine composition. The results of experimental studies of the effect of ammonium polyphosphate and binary mixtures of ammonium polyphosphate (APP) with aluminum hydroxide (AH), sodium tetraborate decahydrate (STD), titanium oxide TiO2 (TO), pentaerythritol (P), aerosil (A) and expandable graphite are presented (EG) on the multiplicity of expanding and weight loss of epoxy compositions at study temperatures of 350, 400 and 450°C. Studies have shown that the production of intumescent flame retardant coatings based on epoxy oligomers is possible provided they are filled with ammonium polyphosphate in an amount of more than 20 mass parts. The most effective in terms of expanding are additives titanium oxide and aluminum hydroxide in an amount of 20 mass parts, which allows to obtain intumescent fire-retardant coatings with a linear coefficient of expanding 30-32 and 24-27, respectively, throughout the range of temperatures. The obtained data are useful in the development of fire-retardant coatings based on epoxy oligomers.

scholarly journals Development and optimization of fire-protective coating composition based on epoxypolymers

2021 ◽  
Vol 4 (3(60)) ◽  
pp. 18-20
Author(s):  
Oleksandr Hryhorenko ◽  
Yevheniia Zolkina
Keyword(s):  
Aluminum Hydroxide ◽  
Experimental Studies ◽  
Fire Retardant ◽  
Epoxy Oligomer ◽  
Carbon Layer ◽  
Response Surfaces ◽  
Ammonium Polyphosphate ◽  
Swelling Ratio ◽  
Coating Composition ◽  
Swelling Coefficient

The object of research is intumescent fire retardant coatings based on epoxy resins. The research is aimed at the development of mathematical models of the dependence of the swelling rate of intumescent fire retardant coatings on their composition. Considering the complexity of the processes during the formation of a protective carbon layer, it is advisable to select the optimal ratio of the components of an intumescent fire retardant coating experimentally, followed by the construction of mathematical dependences of the swelling ratio on the coating composition. Therefore, experimental studies aimed at developing and optimizing the composition of an intumescent fire retardant coating based on epoxy polymers are an important task. The studies were carried out in accordance with the theory of planning experiments with the construction of an orthogonal compositional plan of the second order. A linear swelling factor was chosen as the response function. Compositions based on the ED-20 epoxy oligomer, cured with polyethylene polyamine and filled with ammonium polyphosphate, aluminum hydroxide, and graphite additive were used for the study. Based on the results of processing the experimental results, a regression equation was obtained and response surfaces were constructed that describe the dependence of the linear swelling coefficient Cs of an intumescent composition based on an epoxy oligomer on the content of ammonium polyphosphate, aluminum hydroxide and graphite additive. A complex relationship is shown between the content of components and the linear swelling coefficient Cs with different ratios of the components. The optimum by the linear swelling coefficient (Cs=68.1) content of the components in the epoxy polymer was determined, amounting to 20 wt. including for ammonium polyphosphate, 15 mass parts including for aluminum hydroxide and 3 mass parts for the graphite additive. However, with such a ratio, the «self-extinguishing» condition is not met (Cs=27 %). Filling the composition with ammonium polyphosphate in an amount of 26.3 mass parts including, aluminum hydroxide 25 mass parts and 3.5 mass parts including graphite additives allows to get an intumescent fire retardant coating with a swelling ratio Cs over 63 and a reduced level of flammability (Ci=31 %)

scholarly journals Improved Flame-Retardant and Ceramifiable Properties of EVA Composites by Combination of Ammonium Polyphosphate and Aluminum Hydroxide

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 125 ◽  
Author(s):  
Feipeng Lou ◽  
Kai Wu ◽  
Quan Wang ◽  
Zhongyu Qian ◽  
Shijuan Li ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Aluminum Hydroxide ◽  
Sintering Temperature ◽  
Ethylene Vinyl Acetate ◽  
Ammonium Polyphosphate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Melt Compounding ◽  
Alumina Trihydrate ◽  
Strength Improvement

Ceramifiable flame-retardant ethylene-vinyl acetate (EVA) copolymer composites for wire and cable sheathing materials were prepared through melt compounding with ammonium polyphosphate (APP), aluminum hydroxide (ATH) and fluorophlogopite mica as the addition agents. The effects of ammonium polyphosphate, alumina trihydrate, and APP/ATH hybrid on the flame retardant, as well as on the thermal and ceramifiable properties of EVA composites, were investigated. The results demonstrated that the composites with the ratio of APP:ATH = 1:1 displayed the best flame retardancy and the greatest char residues among the various EVA composites. The tensile strength of the composites was 6.8 MPa, and the residue strength sintered at 1000 °C reached 5.2 MPa. The effect of sintering temperature on the ceramifiable properties, microstructures, and crystalline phases of the sintered specimen was subsequently investigated through X-ray diffraction, Fourier transform infrared, and scanning electron microscopy. The XRD and FTIR results demonstrated that the crystal structure of mica was disintegrated, while magnesium orthophosphate (Mg3(PO4)2) was simultaneously produced at an elevated temperature, indicating that the ceramization of EVA composites had occurred. The SEM results demonstrated that a more continuous and compact microstructure was produced with the rise in the sintering temperature. This contributed to the flexural strength improvement of the ceramics.

scholarly journals ASPECTS OF DEVELOPMENT OF FIREPROOF COMPOSITIONS FOR STRUCTURES WITH TEXTILE FUEL PRODUCTS

2021 ◽  
pp. 93-101
Author(s):  
Yu. Tsapko ◽  
◽  
А. Tsapko ◽  
O. Bondarenko ◽  
M. Suhanevich ◽  
...  
Keyword(s):  
Fire Protection ◽  
Natural Fibers ◽  
Experimental Studies ◽  
Fire Retardant ◽  
Armed Forces ◽  
Textile Material ◽  
Textile Materials ◽  
Coke Layer ◽  
Sample Damage ◽  
Textile Products

The results of experimental studies on the effectiveness of fire protection of easily erected structures made of flammable textile products are presented. An analysis of the directions of use of easily erected structures made of flammable textile products indicates a steady trend towards an increase in their use during the temporary fulfillment of certain tasks of the Armed Forces of Ukraine and units of the. During the heating of such structures, ignition and rapid spread of fire are possible. The operating statistics for easily erected structures have found a low level of safety due to the use of natural fibers (e.g., linen, cotton and blends), which are highly sensitive to heat and fire. Reduction of combustibility and the development of non-combustible and non-combustible materials is one of the main directions for preventing fires and solving the problem of expanding the scope of these materials. Treatment with fire protection means significantly affects the spread of the flame, allows you to reduce the smoke-generating ability and heat release significantly. After the test, it can be seen that the sample of the textile material sustains spontaneous combustion for more than 5 s; sample damage is more than 150 mm. After the test, it is clear that the sample of textile material does not support self-combustion for no more than 5 s; sample damage is no more than 100 mm. The inhibition of the process of ignition and flame propagation for such a sample is associated with the decomposition of fire retardants under the influence of temperature with the absorption of heat and the release of incombustible gases (nitrogen, carbon dioxide), a change in the direction of decomposition towards the formation of incombustible gases and a hardly combustible coke residue. This leads to an increase in the thickness of the coke layer and inhibition of the heat transfer of the high-temperature flame to the material, which indicates the possibility of the transition of textile materials during processing with a fire retardant composition to materials that are non-combustible, which do not spread the flame by the surface.

Effect of Organoclays on Fire Resistance of Siloxane Rubbers

2018 ◽  
Vol 284 ◽  
pp. 25-29 ◽  
Author(s):  
R.N. Gadelshin ◽  
P.V. Ponomarev ◽  
A.R. Kurbangaleeva ◽  
Svetoslav Isaakovich Volfson ◽  
Yu.N. Khakimullin
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Fire Resistance ◽  
Aluminium Hydroxide ◽  
Technological Progress ◽  
Fire Retardant ◽  
Physical And Mechanical Properties ◽  
Practical Significance ◽  
Scientific Interest ◽  
Wide Range

The technological progress constantly raises standards for items operated in rough conditions in order to improve their reliability in a wide range of operating temperatures, fire resistance and sustainability. Researches aimed at discovering flame retardant agents that would help to develop siloxane rubbers with increased fire-resistance are of great scientific interest and have a practical significance. We have studied the effect of aluminium hydroxide on the physical and mechanical properties and fire-resistance of siloxane rubbers. The study has shown that the aluminium hydroxide acts as an effective fire retardant at its content in the rubber over 40 % (wt.), however, it significantly decreases the physical and mechanical properties of the siloxane rubbers and causes difficulties in processing of the rubber mix. The research has shown that the additional introduction of organoclays (5 pts. wt.) improves the fire-resistance of such rubbers, the most effective being montmorillonites modified with alkylbenzyldimethylammonium chloride.

scholarly journals Enhancements on Flame Resistance by Inorganic Silicate-Based Intumescent Coating Materials

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6628
Author(s):  
Sin-Nan Chen ◽  
Pei-Kai Li ◽  
Tar-Hwa Hsieh ◽  
Ko-Shan Ho ◽  
Yu-Meng Hong
Keyword(s):  
Flame Retardant ◽  
Sodium Silicate ◽  
Aluminum Hydroxide ◽  
Weight Ratio ◽  
Ammonium Polyphosphate ◽  
Resistance Testing ◽  
Back Surface ◽  
Expandable Graphite ◽  
Flame Resistance ◽  
Intumescent Coating

Flame-retardant coatings have drawn much attention in recent years. In this study, an inorganic sodium silicate-based intumescent flame-resistance coating with an excellent flameproof properties is developed by mainly utilizing sodium silicate as the ceramizable binder, via hydrolysis and self-condensation reaction. Fly ash, metakaoline, and wollastonite behave as supplement cementing materials. Major formulation encompasses the combination of the ammonium polyphosphate and pentaerythritol as the flame-retardant additives, and aluminum hydroxide or expandable graphite as the intumescence-improving filler agents. Expandable graphite was found to play an important role in the eventual performance of flame-resistance testing. The results showed that solid interaction forces can be formed between metakaoline and sodium silicate, resulting in a similar material to geopolymer with excellent physical properties. After high-temperature flame testing, a densely complex protective layer of carbon-char created on top of the robust silicon dioxide networks offers notable flame resistance. An optimal ratio in this inorganic intumescent coating contains sodium silicate—metakaoline (weight ratio = 9:1)—ammonium polyphosphate and pentaerythritol, aluminum hydroxide (3, 3, 10 wt.%)—expandable graphite (1 wt.%), which can create 4.7 times higher expansion ratio compared with neat sodium silicate matrix. The results of flame testing demonstrate only 387.1 °C and 506.3 °C on the back surface of steel substrate after one and three hours flaming (>1000 °C) on the other surface, respectively, which could meet the requirements according to the level of fire rating.

Synergistic Flame Retardant Effect of Organic Boron Flame Retardant and Aluminum Hydroxide on Polyethylene

2021 ◽  
Vol 22 (2) ◽  
pp. 354-365
Author(s):  
Lianghui Ai ◽  
Shanshan Chen ◽  
Liu Yang ◽  
Ping Liu
Keyword(s):  
Flame Retardant ◽  
Aluminum Hydroxide ◽  
Synergistic Flame Retardant

scholarly journals Image Statistics Preserving Encrypt-then-Compress Scheme Dedicated for JPEG Compression Standard

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 421
Author(s):  
Dariusz Puchala ◽  
Kamil Stokfiszewski ◽  
Mykhaylo Yatsymirskyy
Keyword(s):  
Statistical Analysis ◽  
Image Encryption ◽  
Experimental Studies ◽  
Quality Measures ◽  
Input Image ◽  
Jpeg Compression ◽  
Image Statistics ◽  
Compression Stage ◽  
Wide Range ◽  
The Impact

In this paper, the authors analyze in more details an image encryption scheme, proposed by the authors in their earlier work, which preserves input image statistics and can be used in connection with the JPEG compression standard. The image encryption process takes advantage of fast linear transforms parametrized with private keys and is carried out prior to the compression stage in a way that does not alter those statistical characteristics of the input image that are crucial from the point of view of the subsequent compression. This feature makes the encryption process transparent to the compression stage and enables the JPEG algorithm to maintain its full compression capabilities even though it operates on the encrypted image data. The main advantage of the considered approach is the fact that the JPEG algorithm can be used without any modifications as a part of the encrypt-then-compress image processing framework. The paper includes a detailed mathematical model of the examined scheme allowing for theoretical analysis of the impact of the image encryption step on the effectiveness of the compression process. The combinatorial and statistical analysis of the encryption process is also included and it allows to evaluate its cryptographic strength. In addition, the paper considers several practical use-case scenarios with different characteristics of the compression and encryption stages. The final part of the paper contains the additional results of the experimental studies regarding general effectiveness of the presented scheme. The results show that for a wide range of compression ratios the considered scheme performs comparably to the JPEG algorithm alone, that is, without the encryption stage, in terms of the quality measures of reconstructed images. Moreover, the results of statistical analysis as well as those obtained with generally approved quality measures of image cryptographic systems, prove high strength and efficiency of the scheme’s encryption stage.

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