scholarly journals Investigation of Flame Retardant Flexible Polyurethane Foams Containing DOPO Immobilized Titanium Dioxide Nanoparticles

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 75 ◽  
Author(s):  
Quanxiao Dong ◽  
Keyu Chen ◽  
Xiaodong Jin ◽  
Shibing Sun ◽  
Yingliang Tian ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Heat Release ◽  
Chemical Structure ◽  
Titanium Dioxide Nanoparticles ◽  
Polyurethane Foams ◽  
Fire Performance ◽  
Transmission Electron ◽  
Peak Heat Release Rate ◽  
Microscale Combustion Calorimetry ◽  
Flexible Polyurethane

In this work, a multi-functional nanoparticle (TiO2-KH570-DOPO) has been successfully synthesized through the attachment of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-methacryloxy propyl trimethoxyl silane on the surface of titanium dioxide (TiO2). Supercritical carbon dioxide was used as the solvent in order to increase the grafting level. The chemical structure of TiO2-KH570-DOPO was fully characterized using Fourier transform infrared spectra, thermogravimetric analysis and transmission electron microscopy. The modified TiO2 was incorporated into flexible polyurethane foam (FPUF). The fire performance of FPUF blends was evaluated using microscale combustion calorimetry. Peak heat release rate and total heat release values were reduced from 657.0 W/g and 28.9 kJ/g for neat FPUF sample to 519.2 W/g and 26.8 kJ/g of FPUF specimen containing 10 wt % of TiO2-KH570-DOPO. Analysis of thermal stability and the observation of char formation suggests that TiO2-KH570-DOPO is active in the condensed phase.

Fire Performance of Nylon Nanocomposites Fabricated by Melt Intercalation

2007 ◽  
Vol 334-335 ◽  
pp. 737-740
Author(s):  
Russel J. Varley ◽  
Andrew M. Groth ◽  
Kok Hoong Leong
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Performance ◽  
Fire Retardancy ◽  
Cone Calorimetry ◽  
Char Layer ◽  
Transmission Electron ◽  
Peak Heat Release Rate ◽  
In Fire

This paper presents results of a study carried out to evaluate the effects of an organomodified nanoclay, either on its own or in combination with a polyimide, upon the fire performance of a commercially available nylon. The fire performance, as determined using cone calorimetry showed that up to 40% improvement in the peak heat release rate could be achieved at addition levels of only around 5wt% of nanoclay. The level of improvement was shown to be strongly dependent upon nanoscale dispersion with a more highly exfoliated morphology, as determined using transmission electron microscopy, which showed a greater reduction in the peak heat release rate compared to a more ordered intercalated structure. Investigation of the mechanism of fire retardancy showed that the reduction in the heat release rate is due to the nanoclay reinforcing the char layer which prevented combustible products from entering in to the gaseous phase. Generally, though, the time to ignition is unaffected by nanoclay additions. The addition of the polyimide to the nanoclay reinforced nylon was inconclusive showing little evidence of further improvements in fire performance.

scholarly journals Effects of Various Types of Expandable Graphite and Blackcurrant Pomace on the Properties of Viscoelastic Polyurethane Foams

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1801
Author(s):  
Rafał Oliwa ◽  
Joanna Ryszkowska ◽  
Mariusz Oleksy ◽  
Monika Auguścik-Królikowska ◽  
Małgorzata Gzik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Structure ◽  
Oxygen Index ◽  
Polyurethane Foams ◽  
Expandable Graphite ◽  
Ftir Analysis ◽  
Limiting Oxygen Index ◽  
Peak Heat Release Rate ◽  
Physical And Chemical ◽  
Scanning Electron

We investigated the effect of the type and amount of expandable graphite (EG) and blackcurrant pomace (BCP) on the flammability, thermal stability, mechanical properties, physical, and chemical structure of viscoelastic polyurethane foams (VEF). For this purpose, the polyurethane foams containing EG, BCP, and EG with BCP were obtained. The content of EG varied in the range of 3–15 per hundred polyols (php), while the BCP content was 30 php. Based on the obtained results, it was found that the additional introduction of BCPs into EG-containing composites allows for an additive effect in improving the functional properties of viscoelastic polyurethane foams. As a result, the composite containing 30 php of BCP and 15 php of EG with the largest particle size and expanded volume shows the largest change in the studied parameters (hardness (H) = 2.65 kPa (+16.2%), limiting oxygen index (LOI) = 26% (+44.4%), and peak heat release rate (pHRR) = 15.5 kW/m2 (−87.4%)). In addition, this composite was characterized by the highest char yield (m600 = 17.9% (+44.1%)). In turn, the change in mechanical properties is related to a change in the physical and chemical structure of the foams as indicated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis.

Effect of Sonication Time and Calcination Temperature on Physical Properties of Titanium Dioxide Synthesized via Sonochemical-Assisted Process

2013 ◽  
Vol 802 ◽  
pp. 252-256 ◽  
Author(s):  
Chokchai Kahattha ◽  
Naratip Vittayakorn ◽  
Wisanu Pecharapa
Keyword(s):  
Titanium Dioxide ◽  
Electron Microscope ◽  
Titanium Dioxide Nanoparticles ◽  
Anatase Phase ◽  
Titanium Isopropoxide ◽  
Treatment Temperature ◽  
Sonication Time ◽  
X Ray Diffraction ◽  
Calcination Process ◽  
Transmission Electron

Titanium dioxide nanoparticles (TiO2) were successfully synthesized via a sonochemical-assisted process using titanium isopropoxide as the titanium sources and calcination process at 300-500 °C. The effect of sonication time and heat treatment temperature on structural and nanostructure properties of the nanoparticles were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM). The XRD and Raman results indicated that the crystalline of as-sonochemically synthesized TiO2 nanoparticles corresponded to anatase phase of TiO2 after sonication for 30 mim. The high quality crystalline anatase phase and increasing of crystalline size can be obtained after calcinations process.

scholarly journals The effect of intumescent mat on post-fire performance of carbon fibre reinforced composites

2019 ◽  
Vol 37 (3) ◽  
pp. 257-272 ◽  
Author(s):  
Chenkai Zhu ◽  
Jingjing Li ◽  
Mandy Clement ◽  
Xiaosu Yi ◽  
Chris Rudd ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Reinforced Composites ◽  
Fire Performance ◽  
Total Heat Release ◽  
Reinforced Composite ◽  
Peak Heat Release Rate ◽  
Fibre Reinforced Composites

This study investigated the effect of intumescent mats (M1 and M2) with different compositions on the post-fire performance of carbon fibre reinforced composites. The sandwich structure was designed for composites where M1 (carbon fibre reinforced composite-M1) or M2 (carbon fibre reinforced composite-M2) mats were covered on the composite surface. A significant reduction in the peak heat release rate and total heat release was observed from the cone calorimetric data, and carbon fibre reinforced composite-M1 showed the lowest value of 148 kW/m2 and 29 MJ/m2 for peak heat release rate and total heat release, respectively. In addition, a minor influence on mechanical properties was observed due to the variation of composite thickness and resin volume in the composite. The post-fire properties of composite were characterised, and the M1 mat presented better retention of flexural strength and modulus. The feasibility of two-layer model was confirmed to predict the post-fire performance of composites and reduce the reliance on the large amounts of empirical data.

Ce(IV) Doped TiO2 Nanoparticles and the Effect on Proliferation of BEL7402 Human Hepatoma Cells

2007 ◽  
Vol 330-332 ◽  
pp. 307-310
Author(s):  
L. Wang ◽  
J. Mao ◽  
X.L. Zhang ◽  
M.J. Tu ◽  
B. Kan ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Hepatoma Cells ◽  
Control Group ◽  
Impregnation Method ◽  
Human Hepatoma ◽  
Human Hepatoma Cells ◽  
Transmission Electron ◽  
Induced Apoptosis

To investigate nanoparticles’ antitumor effect, a globose 30~35nm Ce(IV) doped Titanium dioxide nanoparticles (CDT) were prepared by impregnation method and characterized by X-ray diffraction (XRD) and transmission electron microscopy(TEM). Proliferation of BEL7402 human Hepatoma cells was studied in vitro by using fluorescence microscopy and Flow Cytometry. The results show that cerium elements doping enhanced thermal stability of nano-size titanium dioxide to 800°C. With UV irradiated for 8min, BEL7402 were induced a dose-dependent apoptosis by CDT, about 28.2% , 41.5% and 88.3% cells were induced apoptosis after 24h at concentration of 60, 120 and 180ug/ml respectively, relative to 3.9% of that of control group cell just only in the presence of UV.

Bio-camouflage of anatase nanoparticles explored by in situ high-resolution electron microscopy

Nanoscale ◽  
2017 ◽  
Vol 9 (30) ◽  
pp. 10684-10693 ◽  
Author(s):  
Ana R. Ribeiro ◽  
Arijita Mukherjee ◽  
Xuan Hu ◽  
Shayan Shafien ◽  
Reza Ghodsi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
High Resolution Electron Microscopy ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Liquid Cell ◽  
Anatase Nanoparticles

In situliquid cell transmission electron microscopy and graphene liquid cells were used to investigate, thein situnano–bio interactions between titanium dioxide nanoparticles and biological medium.

scholarly journals Studies on the flammability of polypropylene/ammonium polyphosphate and montmorillonite by using the cone calorimeter test

2018 ◽  
Vol 16 (1) ◽  
pp. 108-115 ◽  
Author(s):  
A.A. Hanna ◽  
M.A. Nour ◽  
E.R. Souaya ◽  
M.A. sherief ◽  
A.S. Abdelmoaty
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Acid Treatment ◽  
Ammonium Polyphosphate ◽  
Fire Performance ◽  
Cone Calorimeter Test ◽  
Peak Heat Release Rate

AbstractFire performance of polypropylene (PP) containing different percentages of ammonium polyphosphate (APP) with montmorillonite (Mt) or treated montmorillonite (MtT) was carried out by using the cone calorimeter test (CCT). Different samples from ammonium polyphosphate and montmorillonite were mixed with 90% polypropylene. The characterization of the prepared samples indicates that there is incorporation between the components of the samples. Heat release rate (HRR), peak heat release rate (PHRR), average heat release rate (Av-HRR), and time to ignition (TTI) of the samples were obtained from the cone calorimeter test. Also, the fire performance index (FPI) and the fire growth rate (FIGRA) were calculated. The interpretation of the curves and the parameters results from the cone calorimeter test which indicates that the addition of montmorillonite to APP increases its action as a flame retardant for PP. Moreover, the samples contain acid treatment montmorillonite showed an increase in the efficiency of ammonium polyphosphate when used. This result may be due to an increase in the SiO2 content by acid treatment.

Fire retardant sol–gel coatings for flexible polyurethane foams

RSC Advances ◽  
2016 ◽  
Vol 6 (34) ◽  
pp. 28543-28554 ◽  
Author(s):  
S. Bellayer ◽  
M. Jimenez ◽  
S. Barrau ◽  
S. Bourbigot
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Sol Gel ◽  
Fire Retardant ◽  
Polyurethane Foams ◽  
Fire Growth ◽  
Sol Gel Process ◽  
Flexible Polyurethane

Untreated flexible polyurethane foams used in upholstered products are prone to rapid fire growth. Sol–gel process was evaluated to flame retard it. A successful intumescent formulation gave 60% reduction of the peak of heat release rate.

scholarly journals Influence of Density on Foam Collapse under Burning

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 13
Author(s):  
Abdoul Fayçal Baguian ◽  
Salifou Koucka Ouiminga ◽  
Claire Longuet ◽  
Anne-Sophie Caro-Bretelle ◽  
Stéphane Corn ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Polyurethane Foams ◽  
Pool Fire ◽  
Macroscopic Model ◽  
Infrared Cameras ◽  
Flexible Polyurethane

The fire behaviour of flexible polyurethane foams was studied using a cone calorimeter, with a special emphasis on the collapse step. Only one peak of heat release rate, ranging from 200 to 450 kW/m2, is observed for thin foams, depending on the foam density and the heat flux. On the contrary, heat release rate (HRR) curves exhibit two peaks for 10 cm-thick foams, the second one corresponding to the pool fire formed after foam collapse. In all cases, the collapse occurs at a constant rate through the whole thickness. The rate of the recession of the front was calculated using digital and infrared cameras. Interestingly, its value is relatively constant whatever the heat flux (especially between 25 and 35 kW/m2), probably because of the very low heat conductivity preventing heat transfer through the thickness. The rate increases for the lightest foam but the fraction of burnt polymer during collapse is constant. Therefore, the pool fire is more intense for the densest foam. A simple macroscopic model taking into account only the heat transfer into the foam leads to much lower front recession rates, evidencing that the collapse is piloted by the cell walls’ rigidity.

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