Construction of a Phytic Acid–Silica System in Wood for Highly Efficient Flame Retardancy and Smoke Suppression

The intrinsic flammability of wood restricts its application in various fields. In this study, we constructed a phytic acid (PA)–silica hybrid system in wood by a vacuum-pressure impregnation process to improve its flame retardancy and smoke suppression. The system was derived from a simple mixture of PA and silica sol. Fourier transform infrared spectroscopy (FTIR) indicated an incorporation of the PA molecules into the silica network. Thermogravimetric (TG) analysis showed that the system greatly enhanced the char yield of wood from 1.5% to 32.1% (in air) and the thermal degradation rates were decreased. The limiting oxygen index (LOI) of the PA/silica-nanosol-treated wood was 47.3%. Cone calorimetry test (CCT) was conducted, which revealed large reductions in the heat release rate and smoke production rate. The appearance of the second heat release peak was delayed, indicating the enhanced thermal stability of the char residue. The mechanism underlying flame retardancy was analyzed by field-emission scanning electron microscope coupled with energy-dispersive spectroscopy (SEM-EDS), FTIR, and TG-FTIR. The improved flame retardancy and smoke-suppression property of the wood are mainly attributed to the formation of an intact and coherent char residue with crosslinked structures, which can protect against the transfer of heat and mass (flammable gases, smoke) during burning. Moreover, the hybrid system did not significantly alter the mechanical properties of wood, such as compressive strength and hardness. This approach can be extended to fabricate other phosphorus and silicon materials for enhancing the fire safety of wood.

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Flammability and thermal properties of cotton fabrics modified with a novel flame retardant containing triazine and phosphorus components

Textile Research Journal ◽

10.1177/0040517516652349 ◽

2016 ◽

Vol 87 (11) ◽

pp. 1367-1376 ◽

Cited By ~ 20

Author(s):

Chaohong Dong ◽

Zhou Lu ◽

Peng Wang ◽

Ping Zhu ◽

Xuechao Li ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Cotton Fabric ◽

Flame Retardancy ◽

Decomposition Temperature ◽

Cotton Fabrics ◽

Cone Calorimetry ◽

Limiting Oxygen Index ◽

Untreated Cotton ◽

Index Value

A novel formaldehyde-free flame retardant containing phosphorus and dichlorotriazine components (CTAP) for cotton fabrics was synthesized. As an active group, the dichlorotriazine could react with cotton fabric via covalent reaction. The addition of 20.7 wt% CTAP into the cotton fabric obtained a high limiting oxygen index value of 31.5%, which was 13.5% higher than the pure cotton fabric. The results of heat release rate, total heat release and effective heat combustion indicated that CTAP effectively imparted flame retardancy to cotton fabric by the cone calorimetry test. With respect to the untreated cotton fabrics, the treated cotton fabrics degraded at lower decomposition temperature and form a consistent and compact char layer, which could be observed by thermogravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. Compared to the untreated cotton fabrics, CTAP performed an effective role in flame retardancy for treated cotton fabrics. Meanwhile, it stimulated the formation of char and promoted the thermal stability of treated cotton fabrics during combustion.

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Flame-retardancy and smoke suppression characteristics of bamboo impregnated with silicate-intercalated calcium aluminum hydrotalcates

BioResources ◽

10.15376/biores.16.1.1311-1324 ◽

2020 ◽

Vol 16 (1) ◽

pp. 1311-1324

Author(s):

Yating Hua ◽

Chungui Du ◽

Huilong Yu ◽

Ailian Hu ◽

Rui Peng ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Flame Retardancy ◽

Flame Retardants ◽

Mass Loss Rate ◽

Fire Retardant ◽

Smoke Suppression ◽

Cone Calorimetry ◽

Before And After ◽

Carbon Monoxide Yield

Flame-retardant silicate-intercalated calcium aluminum hydrotalcites (CaAl-SiO3-LDHs) were synthesized to treat bamboo for retardancy, to overcome the bamboo’s flammability and reduce the production of toxic smoke during combustion. The microstructure, elemental composition, flame retardancy, and smoke suppression characteristics of the bamboo before and after the fire-retardant treatment with different pressure impregnation were studied using a scanning electron microscope (SEM), elemental analysis (EDX), and cone calorimetry. It was found that CaAl-SiO3-LDHs flame retardants can effectively fill and cover the cell wall surface and the cell cavity of bamboo without damaging the microstructure. As compared to the non-flame-retardant bamboo, the heat release rate (HRR) of the CaAl-SiO3-LDHs flame-retardant bamboo was significantly reduced, the total heat release (THR) decreased by 31.3%, the residue mass increased by 51.4%, the time to ignition (TTI) delay rate reached 77.8%, the mass loss rate (MLR) decreased, and the carbon formation improved. Additionally, as compared to the non-flame-retardant bamboo, the total smoke release (TSR) of the CaAl-SiO3-LDHs flame-retardant bamboo decreased by 38.9%, and the carbon monoxide yield (YCO) approached zero. Thus, the CaAl-SiO3-LDHs flame-retardant bamboo has excellent flame-retardancy and smoke suppression characteristics.

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Synthesis of a Carrageenan–Iron Complex and Its Effect on Flame Retardancy and Smoke Suppression for Waterborne Epoxy

Polymers ◽

10.3390/polym11101677 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1677 ◽

Cited By ~ 3

Author(s):

Na Wang ◽

Haiwei Teng ◽

Xinyu Zhang ◽

Jing Zhang ◽

Long Li ◽

...

Keyword(s):

Flame Retardancy ◽

Uv Spectroscopy ◽

Thermo Gravimetric Analysis ◽

Iron Complex ◽

Smoke Suppression ◽

Gravimetric Analysis ◽

Cone Calorimetry ◽

Thermo Gravimetric ◽

Limiting Oxygen Index ◽

Waterborne Epoxy

A k-carrageenan–iron complex (KC–Fe) was synthesized by complexation between degraded KC and FeCl3. Furthermore, KC–Fe and ammonium polyphosphate (APP) were simultaneously added into waterborne epoxy (EP) to improve its flame retardancy and smoke suppression performance. The structure and properties of KC–Fe were assessed using Fourier transform infrared spectroscopy (FTIR), ultraviolet (UV) spectroscopy, thermo gravimetric analysis (TGA), and X-ray powder diffraction analysis (XRD). The analysis showed that KC–Fe was successfully synthesized and exhibited good thermal properties with a 49% char residue at 800 °C. The enhanced flame retardancy and smoke suppression performance of waterborne epoxy were evaluated using a limiting oxygen index (LOI) and UL-94. Moreover, the flame retardancy of waterborne epoxy coated on a steel plate was also investigated using cone calorimetry. The results showed that the flame-retardant waterborne epoxy blend exhibited the best flame retardancy when the mass ratio of APP and KC–Fe was 2:1. The total heat release (THR) and total smoke production (TSP) was decreased by 44% and 45%, respectively, which indicated good fire safety performance and smoke suppression properties. Analysis of the residual char using FTIR, SEM, and elemental analysis (EDS) indicated that the action of KC–Fe was promoted by the presence of APP. The formation of a dense thermal stable char layer from an intumescent coating was essential to protect the underlying materials.

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Influence of Zirconium Oxide on Thermal Degradation and Flame Retardancy of Viscose Fibers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.884-885.73 ◽

2014 ◽

Vol 884-885 ◽

pp. 73-77

Author(s):

Cui Cui Song ◽

Quan Ji ◽

Chun Xia Li ◽

Feng Yu Quan ◽

Yan Zhi Xia

Keyword(s):

Thermogravimetric Analysis ◽

Thermal Degradation ◽

Heat Release ◽

Flame Retardancy ◽

Zirconium Oxide ◽

Cellulose Fiber ◽

Cone Calorimetry ◽

Limiting Oxygen Index ◽

Viscose Fibers ◽

Spinning Combustion

We have investigated the effect of zirconium oxide on the thermal degradation and flame retardancy of viscose fibers. ZrO2/cellulose fiber was prepared by wet spinning. Combustion behaviour and flammability were assessed using the limiting oxygen index (LOI) and thermogravimetric analysis from ambient temperature to 800°C and cone calorimetry. LOI results showed that the ZrO2 increased the LOI of viscose fiber from 20% to 26%, which showed that ZrO2 particles had a positive effect on cellulose flame-retardancy. Results from thermogravimetric analysis (TG) indicated that the ZrO2/cellulose fibers produced greater quantities of residues than viscose fibers. The combustion residues were examined using the scanning electron microscopy, indicating that ZrO2/cellulose fiber produced consistent, thick residues. Cone calorimetry indicated that heat release rate and total heat release values of ZrO2/cellulose fiber were less than those of viscose fibers.

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Study on flame retardancy and smoke suppression of PET by the synergy between Fe2O3 and new phosphorus-containing silicone flame retardant

High Performance Polymers ◽

10.1177/0954008320914365 ◽

2020 ◽

Vol 32 (8) ◽

pp. 871-882 ◽

Cited By ~ 2

Author(s):

Yun Peng ◽

Mei Niu ◽

Ruihong Qin ◽

Baoxia Xue ◽

Mingqiang Shao

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Flame Retardancy ◽

Carbon Layer ◽

Smoke Suppression ◽

Limit Oxygen Index ◽

Char Residue ◽

Cone Calorimeter Test ◽

Phosphorus Containing ◽

Index Value

To reduce the environmental hazard from the flame retardant, a halogen-free phosphorus-containing silicone flame-retardant poly N, N dimethylene phosphate aminopropyl siloxane (PDPSI) was prepared following the Mannich reaction. Then, PDPSI and ferric oxide (Fe2O3) were used for the preparation of synergistic flame-retardant polyethylene terephthalate (PET). The flame-retardant test results revealed that at 2% PDPSI/Fe2O3 content and 1:2 mass ratio of PDPSI to Fe2O3, the limit oxygen index value of the PDPSI/Fe2O3/PET composite material was 27.9%, reaching the flame-retardant level and passing the V-0 rating in the UL-94 test. In addition, the PDPSI/Fe2O3/PET composites had a char residue content of 17.5% at 700°C, an increase of 30.6% compared to that of the pristine PET. In the cone calorimeter test, the addition of PDPSI/Fe2O3 significantly reduced the peak heat release rate (PHRR), total heat release (THR) rate, and total smoke production (TSP) value of the resulting PET composites. PHRR and THR decreased by 66.05% and 14.3%, respectively. The TSP value decreased from 14.4 m2 to 8.1 m2, a decrease of 43.8%. The scanning electron microscopy images and Fourier-transform infrared spectra of the char residue showed a significant synergy between Fe2O3 and PDPSI, changing the structure of the carbon layer in continuous and dense form, thus the flame retardancy and smoke suppression of the PET composites improved. In addition, the tensile strength of the PET composite was 42.11 MPa, which was only 1.84% less than that of the pristine PET.

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Flame Retardancy and Mechanical Properties of Chitosan and DOPO with Different Mass Ratios in Epoxy Resin

10.21203/rs.3.rs-1095633/v1 ◽

2021 ◽

Author(s):

Junjie Wang ◽

Xinyu Wang ◽

Chenyu Zhou ◽

Zhiquan Pan ◽

Hong Zhou

Keyword(s):

Mechanical Properties ◽

Heat Release ◽

Epoxy Resin ◽

Flame Retardancy ◽

Synergistic Effects ◽

Resin Matrix ◽

Simultaneous Increase ◽

Combined System ◽

Cone Calorimetry ◽

Limiting Oxygen Index

Abstract This work focused on the effects of chitosan (CS) and 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide (DOPO) on the flammable propertied of epoxy resin matrix. The EP composites were fabricated by direct mixing method through a general curing method. The influence of CS, DOPO and CS / DOPO on the resin was investigated through cone calorimetry tests (CC), UL-94 vertical burning, limiting oxygen index (LOI), thermal gravimetric analyzer (TGA), differential scanning calorimeter (DSC) and thermogravimetric analyzer-Fourier infrared combined system (TG-FTIR). The char residues of modified EPs after CC tests were investigated by FTIR, EDX and XPS. Under the 10% addition of CS / DOPO in EP, with the mass ratio of CS and DOPO of 1 : 1, 1 : 2, 1 : 3, 2 : 1 and 3 : 1, the flame retardancy properties of EPs all increased, but only if EP/10% CS1/DOPO2 and EP/10% CS2/DOPO1 achieved a V-0 rating and their values of LOI were 33.7% and 32.5%, respectively. Compared with EP, the peak heat release rate, peak smoke produce rate and total heat release of EP/10% CS1/DOPO2 and EP/10% CS2/DOPO1 decreased, especially, total smoke release decreased by 61.9% and 71.0%, the char residuals amount increased by 84.3% and 41.6%, and the average CO2 yield decreased by 55.4% and 55.0%, respectively. It is worth nothing that the mechanical properties increased, especially the flexural strength increased by 36.0% and 38.4%, respectively. The results indicated that DOPO and CS had important synergistic effects for simultaneous increase both the flame retardancy and mechanical properties of EP composites.

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Comparison of silicate impregnation methods to reinforce Chinese fir wood

Holzforschung ◽

10.1515/hf-2020-0016 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Ping Li ◽

Yuan Zhang ◽

Yingfeng Zuo ◽

Yiqiang Wu ◽

Guangming Yuan ◽

...

Keyword(s):

Thermal Stability ◽

Heat Release ◽

Flame Retardancy ◽

Chinese Fir ◽

Smoke Suppression ◽

Impregnation Method ◽

Residual Rate ◽

Smoke Production ◽

Human Respiration ◽

Strengthen Effect

AbstractInorganic impregnation strengthening of Chinese fir wood was carried out to improve the strength, dimensional stability, flame retardancy, and smoke suppression of Chinese fir wood. Sodium silicate was used as reinforcement, a sulfate and phosphate mixtures were used as a curing agent, and Chinese fir wood was reinforced by the respiratory impregnation method (RIM) that imitating human respiration and vacuum progressive impregnation method (VPIM). The weight percentage gain (WPG), density increase rate, distribution of modifier, bending strength (BS), compressive strength (CS), hardness, and water resistance of unreinforced Chinese fir wood from the VPIM and RIM were compared. It was found that RIM could effectively open the aspirated pits in Chinese fir wood, so its impregnation effect, strengthen effect and dimension stabilization effects were the best. RIM-reinforced Chinese fir wood was filled with silicate both horizontally and vertically. At the same time, the transverse permeability of silicate through aspirated pits was significantly improved. The chemical structure, crystalline structure, flame retardancy, smoke suppression, and thermal stability of VPIM- and RIM-reinforced Chinese fir wood were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), cone calorimeter (CONE), and thermogravimetric analysis (TGA). The results indicated that although the crystallinity of RIM-reinforced Chinese fir wood decreased the most, more chemical crosslinking and hydrogen bonding were formed in the wood, and the strengthen effect was still the best. Compared with VPIM-reinforced Chinese fir wood, RIM-reinforced Chinese fir wood had lower heat release rate (HRR), peak-HRR, mean-HRR, total heat release (THR), smoke production rate (SPR), and total smoke production (TSP), higher thermal decomposition temperature and residual rate. It was indicated that RIM-reinforced Chinese fir wood was a better flame retardant, and has a smoke suppression effect, thermal stability, and safety performance in the case of fire.

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The Flammability of Polyacrylonitrile and Its Copolymers I. The Flammability Assessment Using Pressed Powdered Polymer Samples

Journal of Fire Sciences ◽

10.1177/073490419301100505 ◽

1993 ◽

Vol 11 (5) ◽

pp. 442-456 ◽

Cited By ~ 14

Author(s):

Jun Zhang ◽

Michael E. Hall ◽

A. Richard Horrocks

Keyword(s):

Flame Retardant ◽

Flame Retardancy ◽

Flame Retardants ◽

Oxygen Index ◽

Char Residue ◽

Acrylic Polymer ◽

Limiting Oxygen Index ◽

Convenient Means ◽

Burning Rates ◽

Polymer Flammability

This paper is the first in a series of four which investigates the burning behaviour and the influence of flame retardant species on the flam mability of fibre-forming polymer and copolymers of acrylonitrile. A pressed powdered polymer sheet technique is described that enables a range of polymer compositions in the presence and absence of flame retardants to be assessed for limiting oxygen index, burning rate and char residue deter minations. The method offers a rapid, reproducible and convenient means of screening possible flame retardant systems, and LOI values compare favourably with those of films and fabrics comprising the same polymeric type. Burning rates, however, are sensitive to changes in physical sample character such as form (film vs. powder sheet) and density. Thus the technique forms an excellent basis for the generation of burning data which will enable comprehensive studies of acrylic polymer flammability and flame retardancy to be undertaken.

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Enhancement of Flame Retardancy of Colorless and Transparent Semi-Alicyclic Polyimide Film from Hydrogenated-BPDA and 4,4′-oxydianiline via the Incorporation of Phosphazene Oligomer

Polymers ◽

10.3390/polym12010090 ◽

2020 ◽

Vol 12 (1) ◽

pp. 90

Author(s):

Xiao Wu ◽

Ganglan Jiang ◽

Yan Zhang ◽

Lin Wu ◽

Yanjiang Jia ◽

...

Keyword(s):

Heat Release ◽

Flame Retardancy ◽

Oxygen Index ◽

Composite Films ◽

Optical Transmittance ◽

Polyimide Film ◽

Total Heat Release ◽

Limiting Oxygen Index ◽

Biphenyltetracarboxylic Dianhydride ◽

Thermal Stability Of

Enhancement of flame retardancy of a colorless and transparent semi-alicyclic polyimide (PI) film was carried out by the incorporation of phosphazene (PPZ) flame retardant (FR). For this purpose, PI-1 matrix was first synthesized from hydrogenated 3,3′,4,4′-biphenyltetracarboxylic dianhydride (HBPDA) and 4,4′-oxydianiline (ODA). The soluble PI-1 resin was dissolved in N,N-dimethylacetamide (DMAc) to afford the PI-1 solution, which was then physically blended with PPZ FR with the loading amounts in the range of 0–25 wt.%. The PPZ FR exhibited good miscibility with the PI-1 matrix when its proportion was lower than 10 wt.% in the composite films. PI-3 composite film with the PPZ loading of 10 wt.% showed an optical transmittance of 75% at the wavelength of 450 nm with a thickness of 50 μm. More importantly, PI-3 exhibited a flame retardancy class of UL 94 VTM-0 and reduced total heat release (THR), heat release rate (HRR), smoke production rate (SPR), and rate of smoke release (RSR) values during combustion compared with the original PI-1 film. In addition, PI-3 film had a limiting oxygen index (LOI) of 30.9%, which is much higher than that of PI-1 matrix (LOI: 20.1%). Finally, incorporation of PPZ FR decreased the thermal stability of the PI films. The 10% weight loss temperature (T10%) and the glass transition temperature (Tg) of the PI-3 film were 411.6 °C and 227.4 °C, respectively, which were lower than those of the PI-1 matrix (T10%: 487.3 °C; Tg: 260.6 °C)

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