Flexural and flammability evaluation of a new bio-based polyurethane foam with alumina trihydrate

2021 ◽  
pp. 146442072098659
Author(s):  
EHP Silva ◽  
GSC Souza ◽  
DB Janes ◽  
G Waldow ◽  
FCP Sales ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foam ◽  
Mass Fraction ◽  
Flexural Modulus ◽  
Flexural Behavior ◽  
Test Results ◽  
Mean Values ◽  
Flammability Test ◽  
Mass Fractions ◽  
Alumina Trihydrate

Flexural and flammability evaluation of a new bio-based polyurethane foam (PUF) with alumina trihydrate (ATH) added as flame retardant were carried out. The PUF was obtained from a blend of vegetable oils. Flexural behavior of the polyurethane with different mass fractions of flame retardant (ATH) was investigated according to ASTM D790-17. Flammability tests were performed according to ASTM D3801-20 and ASTM D635-14 for the vertical and horizontal positions, respectively. The ATH addition influenced the flexural strength of the tested specimens, showing mean values for pure PUF and PUF with 50% of ATH were very close, but the highest value was obtained for PUF with 20% of ATH. Besides, the maximum strain value under flexural load was substantially reduced as the ATH mass increased, which was 11.4% for pure PUF and 3.38% for PUF with 50% of ATH. The flexural modulus increased with ATH incorporation up to 40% mass fraction. The obtained values for pure PUF, PUF with 40% of ATH and PUF with 50% of ATH specimens were 30.63 ± 1.95 MPa, 73.01 ± 2.82 MPa, and 62.16 ± 2.30 MPa, respectively. In addition, flammability test results presented better responses as the amount of ATH increased. PUF with 40% of ATH received V-2 classification, and PUF with 50% of ATH obtained HB classification. Therefore, the results for PUF with the addition of ATH show that the new bio-based material can be designed by using different mass fractions. Thus, this material becomes very useful for many types of applications, such as furniture and automobile industries, as well as sandwich structures and building constructions.

Mechanical and Flammability Properties of Green Polyurethane Foam with Alumina Trihydrate as Flame Retardant

2017 ◽  
Author(s):  
Amanda Silva ◽  
Enio Henrique Pires da Silva ◽  
Danilo Janes ◽  
Romeu Rony Cavalcante da Costa ◽  
Giovanna Gabriela Crem Silva
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foam ◽  
Alumina Trihydrate

Polymer Composite Materials Modified with Nano-Oxides and Phosphinates Hybrid Flame Retardant Systems

2014 ◽  
Vol 634 ◽  
pp. 527-536
Author(s):  
Susana P.B. Sousa ◽  
Maria C.S. Ribeiro ◽  
Paulo R.O. Nóvoa ◽  
Celeste M. Pereira ◽  
António J.M. Ferreira
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Unsaturated Polyester ◽  
Charpy Impact ◽  
Great Sensitivity ◽  
Test Results ◽  
Micro Particles ◽  
Flammability Test ◽  
Composites Materials ◽  
Matrix Modification

Unsaturated polyester based composites materials present several improved properties over conventional materials. However, these composites show great sensitivity to high temperatures and poor fire behaviour. In the present study, an effort is undertaken to develop new unsaturated polyester composites with improved fire reaction behaviour by matrix modification with hybrid flame retardant systems based on nanooxides and phosphinates. For this purpose, a series of composite formulations containing different contents and types of both metal oxide nano/micro particles and organic phosphinates were manufactured, with basis on the Taguchi L9 orthogonal array, and tested for fire reaction and mechanical properties. The data treatment was carried out through analyses of variance. Fire reaction properties were analysed and quantified by the vertical flammability test (UL-94), and the mechanical properties were studied by flexural, Shore D, and Charpy impact tests. The results were compared with those obtained for plain resin specimens. Test results revealed that the addition of hybrid flame retardant systems introduced reasonable improvements in at least one fire reaction property. However, it was verified that the filler addition led to a decrease in mechanical properties, probably due to poor matrix-filler adhesion. Further studies are required in order to improve the mix design formulations.

scholarly journals FLEXURAL BEHAVIOR OF FRP BARS AFTER BEING EXPOSED TO ELEVATED TEMPERATURES

2021 ◽  
Vol 18 (1) ◽  
pp. 12-19
Author(s):  
Dr. Sherif El-Gamal ◽  
Abdulrahman M. Al-Fahdi ◽  
Mohammed Meddah ◽  
Abdullah Al-Saidy ◽  
Kazi Md Abu Sohel
Keyword(s):  
Flexural Strength ◽  
Elevated Temperatures ◽  
Flexural Modulus ◽  
Flexural Behavior ◽  
Test Results ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Significant Strength ◽  
Glass Frp ◽  
Frp Bars

This research study investigates the flexural behavior of fiber reinforced polymer (FRP) bars after being subjected to different levels of elevated temperatures (100, 200 and 300°C). Three types of glass FRP bars (ribbed, sand coated, and helically wrapped) and one type of carbon FRP bars (sand coated) were used in this study. Two testing scenarios were used: a) testing specimens immediately after heating and b) keeping specimens to cool down before testing. Test results showed that as the temperature increased the flexural strength and modulus of the tested FRP bars decreased. At temperatures higher than the glass transition temperature (Tg), significant flexural strength and modulus losses were recorded. Smaller diameter bars showed better residual flexural strength and modulus than larger diameter bars. The immediately tested bars showed significant strength and modulus losses compared to bars tested after cooling. Different types of GFRP bars showed comparable results. However, the helically wrapped bars showed the highest flexural strength losses (37 and 60%) while the sand coated bars showed the lowest losses (29 and 39%) after exposure to 200 and 300℃, respectively. The carbon FRP bars showed residual flexural strengths comparable to those recorded for the GFRP bars; however, they showed lower residual flexural modulus after being subjected to 200 and 300℃.

scholarly journals An Investigation of Flexural Behavior of Pure and Hybrid Wood Composite Panels Using Weibull Analyses

2021 ◽  
Vol 72 (2) ◽  
pp. 201-210
Author(s):  
Abdurrahman Karaman ◽  
H. Ersen Balcioglu
Keyword(s):  
Flexural Modulus ◽  
Medium Density Fiberboard ◽  
Wood Products ◽  
Flexural Behavior ◽  
Composite Panels ◽  
Wood Composite ◽  
Furniture Industry ◽  
Test Results ◽  
Flexural Test ◽  
Distribution Method

The production of inexpensive wood products compared to their strength is important both in terms of economy and meeting the expectations of users. For this purpose, the use of hybrid wood products is increasing in the furniture industry. With the hybridization process, relatively cheap and flimsy material is combined with a material that has a stronger structure. Thus, stronger bonded material is manufactured cheaper. In this study, the flexural behavior of pure and hybrid wood composite panels, which were prepared by applying longitudinal jointing techniques from different wood materials, was investigated. In this context, pure chipboard, pure medium density fiberboard (MDF), chipboard-east beech and MDF-east beech hybrid wood composite panels were produced. During the hybridization process, oriental beech was combined by using the self-grooving technique in three different numbers as one row, two rows, and three rows. Flexural test results were analyzed according to the Weibull distribution method. The results of the analyses showed that the hybridization process increased the flexural strength and flexural modulus of pure wood panels by up to 214 %, and 95 %, respectively.

A technique for uranium and plutonium determination using coulometric potentiostatic facility UPK-19 for analysis of mixed-oxide fuel

2020 ◽  
Vol 86 (12) ◽  
pp. 15-22
Author(s):  
N. A. Bulayev ◽  
E. V. Chukhlantseva ◽  
O. V. Starovoytova ◽  
A. A. Tarasenko
Keyword(s):  
Acid Solution ◽  
Mass Fraction ◽  
Background Electrolyte ◽  
Stable State ◽  
Sulfamic Acid ◽  
Oxide Fuel ◽  
Oxidation Current ◽  
Mox Fuel ◽  
Mass Fractions ◽  
Uranium Plutonium

The content of uranium and plutonium is the main characteristic of mixed uranium-plutonium oxide fuel, which is strictly controlled and has a very narrow range of the permissible values. We focused on developing a technique for measuring mass fractions of uranium and plutonium by controlled potential coulometry using a coulometric unit UPK-19 in set with a R-40Kh potentiostat-galvanostat. Under conditions of sealed enclosures, a special design of the support stand which minimized the effect of fluctuations in ambient conditions on the signal stability was developed. Optimal conditions for coulometric determination of plutonium and uranium mass fractions were specified. The sulfuric acid solution with a molar concentration of 0.5 mol/dm3 was used as a medium. Lead ions were introduced into the background electrolyte to decrease the minimum voltage of hydrogen reduction to –190 mV. The addition of aluminum nitride reduced the effect of fluoride ions participating as a catalyst in dissolving MOX fuel samples, and the interfering effect of nitrite ions was eliminated by introducing a sulfamic acid solution into the cell. The total content of uranium and plutonium was determined by evaluation of the amount of electricity consumed at the stage of uranium and plutonium co-oxidation. Plutonium content was measured at the potentials, at which uranium remains in the stable state, which makes it possible to subtract the contribution of plutonium oxidation current from the total oxidation current. The error characteristics of the developed measurement technique were evaluated using the standard sample method and the real MOX fuel pellets. The error limits match the requirements set out in the specifications for MOX fuel. The technique for measuring mass fractions of uranium and plutonium in uranium-plutonium oxide nuclear fuel was certified. The relative measurement error of the mass fraction of plutonium and uranium was ±0.0070 and ±0.0095, respectively. The relative error of the ratio of the plutonium mass fraction to the sum of mass fractions of uranium and plutonium was ±0.0085.

scholarly journals Numerical Investigation of the Effect of Air Leaking into the Working Fluid on the Performance of a Steam Ejector

2021 ◽  
Vol 11 (13) ◽  
pp. 6111
Author(s):  
He Li ◽  
Xiaodong Wang ◽  
Jiuxin Ning ◽  
Pengfei Zhang ◽  
Hailong Huang
Keyword(s):  
Flow Structure ◽  
Mass Fraction ◽  
Internal Flow ◽  
Working Fluid ◽  
Physical Parameters ◽  
Entrainment Ratio ◽  
Air Mass ◽  
Steam Ejector ◽  
Primary Fluid ◽  
Mass Fractions

This paper investigated the effect of air leaking into the working fluid on the performance of a steam ejector. A simulation of the mixing of air into the primary and secondary fluids was performed using CFD. The effects of air with a 0, 0.1, 0.3 and 0.5 mass fraction on the entrainment ratio and internal flow structure of the steam ejector were studied, and the coefficient distortion rates for the entrainment ratios under these air mass fractions were calculated. The results demonstrated that the air modified the physical parameters of the working fluid, which is the main reason for changes in the entrainment ratio and internal flow structure. The calculation of the coefficient distortion rate of the entrainment ratio illustrated that the air in the primary fluid has a more significant impact on the change in the entrainment ratio than that in the secondary fluid under the same air mass fraction. Therefore, the air mass fraction in the working fluid must be minimized to acquire a precise entrainment ratio. Furthermore, this paper provided a method of inspecting air leakage in the experimental steam ejector refrigeration system.

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

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.

Numerical and Experimental Investigation Into the Effects of Nanoparticle Mass Fraction and Bubble Size on Boiling Heat Transfer of TiO2–Water Nanofluid

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Cong Qi ◽  
Yongliang Wan ◽  
Lin Liang ◽  
Zhonghao Rao ◽  
Yimin Li
Keyword(s):  
Heat Transfer ◽  
Bubble Size ◽  
Boiling Heat Transfer ◽  
Mass Fraction ◽  
Experimental Methods ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Mass Fractions ◽  
Boiling Heat Transfer Coefficient ◽  
Bubble Sizes

Considering mass transfer and energy transfer between liquid phase and vapor phase, a mixture model for boiling heat transfer of nanofluid is established. In addition, an experimental installation of boiling heat transfer is built. The boiling heat transfer of TiO2–water nanofluid is investigated by numerical and experimental methods, respectively. Thermal conductivity, viscosity, and boiling bubble size of TiO2–water nanofluid are experimentally investigated, and the effects of different nanoparticle mass fractions, bubble sizes and superheat on boiling heat transfer are also discussed. It is found that the boiling bubble size in TiO2–water nanofluid is only one-third of that in de-ionized water. It is also found that there is a critical nanoparticle mass fraction (wt.% = 2%) between enhancement and degradation for TiO2–water nanofluid. Compared with water, nanofluid enhances the boiling heat transfer coefficient by 77.7% when the nanoparticle mass fraction is lower than 2%, while it reduces the boiling heat transfer by 30.3% when the nanoparticle mass fraction is higher than 2%. The boiling heat transfer coefficients increase with the superheat for water and nanofluid. A mathematic correlation between heat flux and superheat is obtained in this paper.

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