Flammability Research Papers - Academia.edu (original) (raw)

Untreated polyurethane flexible foams (PUFs) are prone to rapid fire growth due to their low density and low thermal conductivity. Furthermore, the low viscosity of the decomposition products generates severe dripping that increases the... more

Untreated polyurethane flexible foams (PUFs) are prone to rapid fire growth due to their low density and low thermal conductivity. Furthermore, the low viscosity of the decomposition products generates severe dripping that increases the fire hazard related to the combustion of PUFs. In fact, this downward flow of flaming liquid often results in a pool-fire that promotes flame propagation and boosts the rate of heat release (HRR) due to a significant increase in the burning area and to feed-back between the flame on the pool-fire and the residual foam. In this work the effect of nanoparticles, i.e., clays and carbon nanofibers (CNFs), on the HRR is investigated with special attention given to melt dripping. A modified cone calorimeter test has been developed for this purpose. It is shown that CNFs form an entangled fiber network which eliminates melt dripping and decreases the HRR. Published in 2008 by John Wiley & Sons, Ltd.

This work presents a burner design methodology for pyrolysis gas emitted from charcoal production. Based on the variety of the existing burner concepts the flameless oxidation concept was chosen due to its high stability, energy recovery... more

This work presents a burner design methodology for pyrolysis gas emitted from charcoal production. Based on the variety of the existing burner concepts the flameless oxidation concept was chosen due to its high stability, energy recovery capability and possibility to deal with dirty gas with presence of tar. An analysis of the flammability limits of the pyrolysis gas showed that it is flammable most of the operation time. A design methodology was carried and a prototype is presented. The prototype is proposed to be placed on the top of the charcoal kiln chimney. Tests are due to be run by the end of this year at a biomass valorization plant in Minas Gerais, Brazil. Keywords: Combustion, flameless oxidation, pyrolysis, gas, charcoal production

The cost of construction materials and the required natural resources to produce the materials with the enabling environment is affecting the world's construction industry which is growing at an alarming rate. Also, plastic wastes have... more

The cost of construction materials and the required natural resources to produce the materials with the enabling environment is affecting the world's construction industry which is growing at an alarming rate. Also, plastic wastes have posed a major threat to the environment due to their large usage, non-biodegradability nature, and pollution through incineration and landfill. Recycling these wastes into tiles will be a great advantage. This study aims at examining mechanical properties of tile made from PET (Polyethylene Terephthalate) wastes, fly ash, and river sand aggregate. The PET wastes of varying percentages of 100%, 90%, 70%, 50%, and 30% by weight to other aggregates. The evaluation of physical and mechanical properties shows that, in terms of material density, strength, and flammability resistance, the tiles with 30% of the plastic waste yields better results than other proportions of the waste. According to the results obtained, this composite tile has a very low % porosity value (2.8-0.11%) compared to cement or ceramic tiles. Also, the composite tile (PFST1) with 30% and 35% sand and fly ash displayed lower flammability of 7.76mm/min linear burning rate and enhanced compressive strength of 11.10 MPa. The chemical tolerance of these composite tiles was also investigated by soaking in different acid, base, and alkaline for seven days, which has no significant difference in terms of weight and appearance. In conclusion, PET plastic tiles have good strength, decrease flammability, low water absorption, and eco-friendliness as tiles products. This prospect would not only minimize the cost of building products but will also act as a waste diversion to mitigate the environment caused by plastic waste disposal.

In this study, the flame retardancy properties of huntite/hydromagnesite mineral in plastic compounds were investigated for potential electrical applications. Before the production of composite materials, huntite/hydromagnesite minerals... more

In this study, the flame retardancy properties of huntite/hydromagnesite mineral in plastic compounds were investigated for potential electrical applications. Before the production of composite materials, huntite/hydromagnesite minerals were ground to particle sizes of 10, 1, and 0.1 μm. Phase and microstructural analysis of huntite/hydromagnesite mineral powders were undertaken using XRD and SEM-EDS preceding the fabrication of the composite materials. The ground minerals with different particle size and content levels were subsequently added to ethylene vinyl acetate copolymer to produce composite materials. After fabrication of huntite/hydromagnesite reinforced plastic composite samples, they were characterized using DTA-TG, FTIR, and SEM-EDS. Flame retardancy tests were undertaken as a main objective of this research. The size distribution and the mineral content effects are measured regarding the flame retardancy of the polymer composites It was concluded that the flame retardant properties of plastic composites were improved as the mineral content increased and the size was reduced. POLYM. COMPOS., 31:1692–1700, 2010. © 2010 Society of Plastics Engineers.

Interfacial properties, crystallinity and flammability of short fiber reinforced and flame retarded polyamide 6 and polyamide 66 compounds are investigated, emphasizing the influence of flame retardant fillers on the resistance of... more

Interfacial properties, crystallinity and flammability of short fiber reinforced and flame retarded polyamide 6 and polyamide 66 compounds are investigated, emphasizing the influence of flame retardant fillers on the resistance of fiber/matrix interface to shear. Interfacial shear strengths are derived through a micromechanical approach by determining the tensile properties and residual fiber length distributions. Validated by fracture morphologies, interfacial strengths are found to be governed by filler – induced apparent crystallinities and fractional occurrence of polyamide polymorphs, obtained via peak deconvolution of X-Ray diffraction patterns. Although flame retardant additives based on Br/Sb synergism are found to impart excellent flammability reductions regarding oxygen index and UL94 classifications (V-0 rating), degree of crystallinity; thus, interfacial properties are deteriorated due to lowered thermal expansion and increased cooling rates. Red phosphorus as a flame retardant also induces a UL94 V-0 and significant reduction in flammability together with the facts that crystallinity is not altered and a strong fiber/matrix interface is maintained. Use of melamine cyanurate in an unreinforced polyamide improves the limiting oxygen index considerably; however, the UL94 rating remains unchanged as V-2 as a consequence of increased level of melt dripping. Melamine cyanurate additionally increases the degree of crystallinity through promotion of heterogeneous nucleation.

Woven hemp fabric was treated with sodium hydroxide, commercial flame retardant chemical, and combination of both to increase its fire-retardant properties. Treatments of fire-retardant changed the properties of woven hemp fabric such as... more

Woven hemp fabric was treated with sodium hydroxide, commercial flame retardant chemical, and combination of both to increase its fire-retardant properties. Treatments of fire-retardant changed the properties of woven hemp fabric such as increased its fabric shrinkage and density of fibres which ranges from 0.67 to 5% and 1.43 to 1.53 g/cm 3 respectively. After the treatment, the fire retardancy of the fabric increased tremendously which was observed by the burning, thermogravimetry and limiting oxygen index tests. Some of the samples were not burnt when exposed to flame source and the burning rate needed to be measured under exaggeration of flame at longer time. The limiting oxygen index value increased from 18.6 to 51 after the treatments which explained the scenario happened in the burning tests. Nevertheless, its mechanical properties decreased slightly that ranges from 18 to 32% and 23 to 39% for warp and weft respectively compared to untreated fibre.

Aim: The purpose of the research was to determine the effect of the addition of melamine and silica in the retanning process on selected properties of leather with particular regard to flammability. The article presents the results of... more

Aim: The purpose of the research was to determine the effect of the addition of melamine and silica in the retanning process on selected properties of leather with particular regard to flammability. The article presents the results of work related to the processing of leather at the retanning stage. Various amounts of silica and melamine were used in retanning in order to achieve a higher resistance of leather to flammability.
Methods: The work involved experimental tests, which included retanning of natural leather and testing of selected properties of the leathers obtained. Retanning was carried out on a laboratory scale. The leather testing included parameters related to the comfort of using leather goods such as softness and water vapor permeability. Flammability tests of leather were carried out using specifically developed methods. The tests of flame resistance of
leather under conditions of limited access of oxygen were also carried out. In addition, the hydrothermal resistance of the resulting hides was determined.
Results: The composition of a retanning mixture and the results of the leather properties tests were the basis for the optimisation and determination of the effect of melamine and silica on the examined properties of leather. The results of investigations of the properties of retanned leather show a correlation between the amount of additives in retanning and on the flammability of the leather.
Conclusions: Based on the conducted tests, it was found that:
1. The increase in the amount of melamine and silica used in the composition of the mixture increases the resistance of leather samples to burning through (with the influence of melamine being the more important of the two).
2. Retanning both with additives (silica and melamine) and without additives only slightly reduces the water vapour permeability for all tested variants. Retanning leads to an increase in the shrinkage temperature by max. 4°C.
3. The results of the optimisation show that the compromise optimum with the assumed properties of the leather is obtained with the addition of melamine and silica in the retanning mixture at 0.06–0.5% for silica and 0.35–0.65% for melamine under the test conditions.
Keywords: natural leather, flammability, melamine, silica, retanning, optimisation
Type of article: original scientific article

This study aims to synthesize poly(methylsilyne) by electrochemical reduction of methyltrichlorosilane at a constant potential of −6 V, while investigating the effects of parameters such as the nature of the electrode, solvent and... more

This study aims to synthesize poly(methylsilyne) by electrochemical reduction of methyltrichlorosilane at a constant potential of −6 V, while investigating the effects of parameters such as the nature of the electrode, solvent and supporting electrolyte, the monomer/solvent ratio, and the reaction time on the properties of the products. The polymer was characterized by 1H-NMR (Proton Nuclear Magnetic Resonance Spectroscopy), FTIR (Fourier Transform Infrared Spectroscopy), UV-Visible Spectroscopy, and TGA (Thermogravimetry Analysis). Copper (Cu) electrodes were used as stainless steel introduced impurities into the system. In an electrolytic media consisting of acetonitrile (AN), sodium dodecyl sulfate (SDS), and Cu electrodes, increasing the monomer/solvent ratio and the reaction time affected the system negatively based on the purity of poly(methylsilyne) in the final product. Reproducible results were only achieved in an electrolytic media containing 1,2-dimethoxyethane (DME) and tetrabutylammonium perchlorate (TBAP). In this system, the purity of the products was less dependent on monomer/solvent ratio and reaction time. The color and the 1H-NMR, FTIR, and UV-Visible spectra proved that the product is poly(methylsilyne). In addition, the significantly high-average decomposition temperature obtained from TGA results revealed that the polymer is a good candidate as an additive for improving thermal stability and flame retardancy in thermoplastics. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Monofunctional Polyhedral Oligomeric Silsesquioxanes (POSS), differing in chemical structure, were introduced into an epoxy-amine formulation in order to obtain hybrid organic/inorganic epoxy networks. The process developed allows the... more

Monofunctional Polyhedral Oligomeric Silsesquioxanes (POSS), differing in chemical structure, were introduced into an epoxy-amine formulation in order to obtain hybrid organic/inorganic epoxy networks. The process developed allows the POSS to be either covalently bonded to the network and organized in small amorphous domains, or completely dispersed in larger crystalline domains. Morphology, thermal and fire retardant properties were studied through electron

Non-durable and semi-durable flame retardants based mostly on phosphate or phosphonate salts continue to be used on infrequently washed or disposable goods, and recent improvements have been made to impart better `hand' or some... more

Non-durable and semi-durable flame retardants based mostly on phosphate or phosphonate salts continue to be used on infrequently washed or disposable goods, and recent improvements have been made to impart better `hand' or some limited wash resistance. Backcoating with insoluble ammonium polyphosphate, usually with additives and binders to provide intumescence, has been found effective on charrable fabrics. However, the leading backcoating effective on a wider range of fabrics, including synthetics and blends, is decabromodiphenyl ether plus antimony oxide. Newer candidates in development for textile coating are polymers and copolymers of pentabromobenzyl acrylate. The leading durable finish for cellulosic fibers, in use for about 50 years, continues to be based on tetrakis(hydroxymethyl)phosphonium salts reacted with urea and cured with gaseous ammonia. Softer versions have been recently developed using chemical or process modifications, or using selected fiber blends. Somewhat...