Materials engineering for surface-confined flame retardancy (original) (raw)
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Novel Environmental Friendly Fire Retardants
Advances in Sciences and Engineering
Nowadays flame-retardant chemicals are mandatory in many products worldwide, flame-retardant chemicals are mandatory in many products worldwide, since they protect human life and property. Over the past few decades the use of flame-retardant chemicals has increase. Flame-retardant polymeric materials have spawned huge research interest in both scientific and industrial communities due to their broad range of applications in the fields of aviation, automotive industry, construction, electronics and telecommunications. The use of conventional FRs to meet the fire safety standards is of serious importance as they ultimately yield POPs of global concern. Considering eco-friendliness and other required properties, unsatisfactory fire performance is a major obstacle. The aim of this article is to provide an overview of traditional, commonly used flame retardants, as well as an overview of new, more environmentally acceptable alternatives.
Polymers in Fire Protection, 2023
In this entry, fire protection of polymeric materials has been discussed with respect to flameretardant polymers as well as additives employed. Flame retardants for polymer and their potential suitability for use in fire applications have been reviewed. Five principle types of flame retardants were discussed for inclusion in polymers, namely halogen, phosphorus, nitrogen, silicon, and organic flame retardants. In this regard, the choice of polymer matrix, additive, processing techniques and characterization method is important for the formulation of high-performance nonflammable system. The influence of polymers and modified flame retardant addition on flame retardation and smoke suppression features have been investigated using cone calorimetric methods, limiting oxygen index measurement, and thermogravimetric analysis. Consequently, it was observed that with increasing flame retardant content, significant enhancement in flame retardancy features may occur.
Halogenated Flame Retardants: Do the Fire Safety Benefits Justify the Risks?
Reviews on …, 2010
Since the 1970s, an increasing number of regulations have expanded the use of brominated and chlorinated flame retardants. Many of these chemicals are now recognized as global contaminants and are associated with adverse health effects in animals and humans, including endocrine and thyroid disruption, immunotoxicity, reproductive toxicity, cancer, and adverse effects on fetal and child development and neurologic function. Some flame retardants such as polybrominated diphenyl ethers (PBDEs) have been banned or voluntarily phased out by manufacturers because of their environmental persistence and toxicity, only to be replaced by other organohalogens of unknown toxicity. Despite restrictions on further production in some countries, consumer products previously treated with banned retardants are still in use and continue to release toxic chemicals into the environment, and the worldwide use of organohalogen retardants continues to increase. This paper examines major uses and known toxic effects of commonly-used organohalogen flame retardants, replacements for those that have been phased out, their combustion by-products, and their effectiveness at reducing fire hazard. Policy and other solutions to maintain fire safety while reducing toxicity are suggested. The major conclusions are: (1) Flammability regulations can cause greater adverse environmental and health impacts than fire safety benefits. (2) The current options for end-of-life disposal of products treated with organohalogens retardants are problematic. (3) Life-cycle analyses evaluating benefits and risks should consider the health and environmental effects of the chemicals, as well as their fire safety impacts. (4) Most fire deaths and most fire injuries result from inhaling carbon monoxide, irritant gases, and soot. The incorporation of organohalogens can increase the yield of these toxic by-products during combustion. (5) Fire-safe cigarettes, fire-safe candles, child-resistant lighters, sprinklers, and smoke detectors can prevent fires without the potential adverse effects of flame retardant chemicals. (6) Alternatives to organohalogen flame retardant chemicals include using less flammable materials, design changes, and safer chemicals. To date, before evaluating their health and environmental impacts, many flame retardant chemicals have been produced and used, resulting in high levels of human exposure. As a growing literature continues to find adverse impacts from such chemicals, a more systematic approach to their regulation is needed. Before implementing new flammability standards, decision-makers should evaluate the potential fire safety benefit versus the health and environmental impacts of the chemicals, materials, or technologies likely to be used to meet the standard. Reducing the use of toxic or untested flame retardant chemicals in consumer products can protect human and animal health and the global environment without compromising fire safety. S. SHAW ET AL.
Flame Retardant Coatings: Additives, Binders, and Fillers
Polymers
This review provides an intensive overview of flame retardant coating systems. The occurrence of flame due to thermal degradation of the polymer substrate as a result of overheating is one of the major concerns. Hence, coating is the best solution to this problem as it prevents the substrate from igniting the flame. In this review, the descriptions of several classifications of coating and their relation to thermal degradation and flammability were discussed. The details of flame retardants and flame retardant coatings in terms of principles, types, mechanisms, and properties were explained as well. This overview imparted the importance of intumescent flame retardant coatings in preventing the spread of flame via the formation of a multicellular charred layer. Thus, the intended intumescence can reduce the risk of flame from inherently flammable materials used to maintain a high standard of living.
Combustion and fire retardance in polymeric materials
Le Journal de Physique IV, 1993
The use of organic polymeric materials is limited in many applications because of fire hazard. Fire retardant systems have been found which reduce this hazard below acceptable levels. The development of more efficient systems is constantly pursued to meet the demand for ever safer materials. This involves the difficult problems of the testing methods and of the mechanistic approach which should supply information for progressing in this task. Examples of mechanistic studies on halogen based or intumescent fire retardant are illustrated.
Ecological issue of polymer flame retardancy
Journal of Applied Polymer Science, 2002
The use of polymer flame retardants has an important role in saving lives. The main flame retardant systems for polymers currently in use are based on halogenated, phosphorous, nitrogen, and inorganic compounds. All of these flame retardant systems basically inhibit or even suppress the combustion process by chemical or physical action in the gas or condensed phase. Conventional flame retardants, such as halogenated, phosphorous, or metallic additives, have a number of negative attributes. An ecological issue of the application of conventional flame retardants demands the search of new polymer flame retardant systems. Among the new trends of flame retardancy are intu-mescent systems, polymer nanocomposites, preceramic additives, low-melting glasses, different types of char formers, and polymer morphology modification processing. The brief explanations on the three major types of flame retardant systems (intumescent systems, polymer nanocomposites, and polymer organic char formers) are the subject of this overview.
Development of additives possessing both solid-phase and gas-phase flame retardant activities
Polymer Degradation and Stability, 2008
Effective additives are required to impart a measure of fire retardancy to polymeric materials used in a variety of applications. Traditionally, these have been gas-phase active additives, most commonly organohalogen compounds or solid-phase active agents, often organophosphorus compounds. Organosphosphorus flame retardants are often very effective but may suffer from a cost disadvantage when compared with their organobromine counterparts. Organohalogen flame retardants are usually quite effective but their use is a subject to several environmental concerns. The development of additives that could simultaneously promote both types of fire retardant action could make available flame retardants that are both more cost effective and more environmentally friendly than those currently in use. Several sets of compounds with the potential to display both solid-phase and gas-phase flame retardant activities have been prepared and evaluated.
Advancements in traditional and nanosized flame retardants for polymers—A review
Journal of Applied Polymer Science, 2020
Synthetic polymers are ubiquitous materials widely used in construction, automotive, electronics, and countless commercial products. With the growing trend of polymer applications in everyday life, upholding the rigorous fire safety regulations has become a matter of concern. In this regard, numerous studies have been conducted for improving the fire retardancy of polymers, mainly through incorporating a diverse group of fire‐retardant compounds into polymer‐based composites. This review article aims to present a comprehensive overview of recent advances in the fire‐retardant categories for polymeric materials especially emphasizing the nanosized fire retardants. Along with an attempt to focus attention on the consumption of conventional and possibly harmful fire retardants, potential eco‐friendly alternatives are represented. A detailed discussion on the flame retardation mechanisms and conventional fire characterization techniques are also discussed.
Fire and Materials, 2014
This is part of a project considering whether flame retardants affect polymer heat release, a critical issue to assess whether adding flame retardants decreases fire hazard. The work investigated the following. (1) Fire properties affecting fire hazard, confirming that heat release rate is the key fire property most strongly influencing fire hazard. (2) Ways to assess heat release and whether full-scale fire heat release rate can be predicted from small-scale test results, confirming that cone calorimeter and Ohio State University data are adequate to predict full-scale heat release. (3) Analysis of key 1988 NBS/NIST study comparing the fire hazard of flame retarded products versus non-flame retarded products for the same application. This confirmed that the study demonstrated that flame retardants lower fire hazard and that the levels of additives in the flame retarded products used were not excessive. (4) Review of studies investigating effects of flame retardants on various polymeric systems. The overall conclusion is that flame retardants does indeed improve fire safety (when used appropriately) primarily because they decrease heat release. Part 2 of the project (separately) considers the key polymers that need to be potentially flame retarded and reviews recent studies on effects of flame retardants on heat released by such polymers.