The synthesized flame retardant 9,10-dihydro-9-oxa-10-phosphaphanthrene-10-oxide/vinyl methyl dimethoxysilane (DV) was used to modify multiwalled carbon nanotubes (MWNTs). The results of FTIR, 1H-NMR, and TGA measurements show that DV has been covalently grafted onto the surfaces of MWNTs, and the MWNTs-g-DV is obtained successfully. Transmission electron microscopy images show that a core-shell nanostructure appears with MWNTs as the core and the DV thin layers as the shell, and the modified MWNTs with DV can achieve better dispersion than unmodified MWNTs in EVM matrix. Thermogravimetric analysis and cone calorimeter tests indicate that the thermal stability and flame retardant are improved for the presence of the MWNTs in EVM matrix. Moreover, the improvement is more evident for EVM/MWNTs-g-DV composite compared to unmodified MWNTs-based composite, which can be attributed to the better dispersion of the DV-modified MWNTs and to the chemical structure of the combustion residue. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Thermal and flame retardant properties of ethylene‐vinyl acetate copolymer/modified multiwalled carbon nanotube composites

The purpose of this study is to review and summarise the existing available literature on lightweight cladding systems to provide detailed information on fire behaviour (ignitibility, heat release rate and smoke toxicity) and various test method protocols. Additionally, the paper discusses the challenges and provides updated knowledge and recommendation on selective-fire mechanisms such as rapid-fire spread, air cavity and fire re-entry behaviours due to dripping and melting of lightweight composite claddings.,A comprehensive literature review on fire behaviour, fire hazard and testing methods of lightweight composite claddings has been conducted in this research. In summarising all possible fire hazards, particular attention is given to the potential impact of toxicity of lightweight cladding fires. In addition, various criteria for fire performance evaluation of lightweight composite claddings are also highlighted. These evaluations are generally categorised as small-, intermediate- and large-scale test methods.,The major challenges of lightweight claddings are rapid fire spread, smoke production and toxicity and inconsistency in fire testing.,The review highlights the current challenges in cladding fire, smoke toxicity, testing system and regulation to provide some research recommendations to address the identified challenges.

Flame behaviour, fire hazard and fire testing approach for lightweight composite claddings – a review

Fundamental suppression chemistry of clean fire suppressing agents : a review

Many big building fires happened in the past involved burning furniture foam. In some places such as Hong Kong, foams treated with fire retardant additives are only required to test their ignitability under a small flame. It was proposed earlier that the behaviour of furniture foam in flashover fires should be assessed more extensively by a cone calorimeter under high radiative heat fluxes. In this paper, this screening approach is further studied using five samples, including three different pillow foams, one mattress foam and one expensive fire-safe sofa foam. Both thermal and smoke aspects were studied in a cone calorimeter under heat fluxes of 20 kWm-2, 30 kWm-2, 50 kWm-2 and 70 kWm-2. It was observed that all the foam samples were burnt under heat fluxes above 30 kWm-2. Only one pillow foam sample was not ignited under a low incident heat flux of 20 kWm-2, but it morphed into a mixture of solid and liquid. Under heat fluxes above 30 kWm-2, the fire-safe foam burnt vigorously; the burning showed no differences from foam without fire retardant. The fire-safe foam even released more smoke and toxic gases with higher carbon monoxide concentration. From the above cone calorimeter test, foams commonly used in the market can only withstand small match fires to delay ignition time. Foam products should be protected by additional provisions, such as an external cover, to protect them against big fires.

Proposed fire screening tests on plastic foams with a cone calorimeter in Hong Kong

Building polymers are highly flammable and produce a vast amount of toxic chemical compounds in the event of a fire which can lead to potential incapacitation and death. To gain an in-depth understanding of this issue, smoke toxicity and thermal characteristics of seven commonly used building polymers were analysed through a systematic fire performance evaluation system using a Thermogravimetric Analyzer and a Cone Calorimeter coupled with an FTIR arrangement. Four Fractional Effective Dose (FED) expressions were compared to assess the smoke toxicity of the fire effluents based on different assumptions. It was found that FEDN2, calculated using Purser’s equation, reported the highest values of FED with the following order of potential smoke toxicity at 50 kW/m2 radiative heat flux: LDPU > HDPU > PE > HDEPS > XPS > EVA > LDEPS. Furthermore, fire performance evaluation of the polymers was carried out by considering three key fire risk parameters, i.e., flashover propensity, total heat released, and toxic hazard. At 50 kW/m2 radiative heat flux, HDPU exhibited 11.7 times flashover propensity compared to the least flammable polymer (HDEPS), EVA exhibited 5 times total heat release compared to the polymer with the lowest total heat release (LDEPS) and, LDPU exhibited 6.7 potential times toxic hazard compared to the least toxic polymer (EVA).

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Thermal Hazard and Smoke Toxicity Assessment of Building Polymers Incorporating TGA and FTIR—Integrated Cone Calorimeter Arrangement

Both thermal and smoke aspects on typical samples of furniture foams with and without fire retardants available in the market were tested with a cone calorimeter. To study their behaviour under big fires, high incident radiative heat fluxes up to 70 kWm -2 were adjusted. Transient curves on heat release rate, mass loss rate, carbon monoxide concentration, carbon dioxide concentration, smoke release rate and other key parameters were measured. Further, chemical constituents of the fire retardants were analyzed by X-ray fluorescence, Fourier Transform Infrared, Gas Chromatography/ Mass Spectrometry and Pyrolysis Gas Chromatography Mass Spectrometry. It is observed that foam treated with fire retardant would not be ignited under an incident heat flux of 10 kWm -2 . However, when burning under heatfluxes higher than 20 kWm -2 , there is not much improvement in the thermal aspect for foam treated with fire retardants. Even more smoke and toxic gases such as carbon monoxide was emitted. Therefore, testing ignitibility offurniturefoam materials under a small match flame is not adequate. Tests with high radiative heat flux encountered in big fires are suggested. Cone calorimeter tests proposed in this paper would give a better assessment onfire safety. Finally, three risk parameters are proposed to work out a combustibility database.

S. S. Han

Papers

Assessment of Fire Performance of Typical Furniture Foams with and without Fire Retardants Using a Cone Calorimeter

Proposed fire screening tests on plastic foams with a cone calorimeter in Hong Kong