Flame retardants trends

J. Murphy, Flame retardants Trends and new developments. Plastics Additives and Compounding, 3 (2001), 16-20. 

Trends in the research and development of phosphoms flame retardants have been in the direction of less volatile, less toxic, more stable compounds, and where feasible, in the direction of built-in phosphoms stmctures. At the same time, there have been an increasing number of regulatory delays in new compounds, and the existent materials are finding increased exploitation in the form of mixtures. Some interest is also noted in encapsulation. 

However, from a commercial standpoint, modifying the polymer mainly for improved flame retardancy is usually done reluctantly, since other properties usually suffer and cost is generally increased. The present trend for developing improved polymers is to utilize polyblending. Can a polyblending approach achieve efficient flame retardancy ... 

UBA remarked that It is encouraging that there is a general trend to refrain from the use of halogenated flame retardants in products and to replace them with less problematic flame retardants or to redesign flame retardant systems, e.g. by creating greater distances to potential heat sources. ... 

Thomsen C, Lundanes E, Becher G (2002) Brominated flame retardants in archived serum samples from Norway a study on temporal trends and the role of age. Environ Sci Techn 36 1414-1418... 

Quintana JB, Rodil R, Reemstma T, Garcia-Lopez M, Rodriguez I (2008) Organophosphorus flame retardants and plasticizers in water and air II. Anal Methodol Trac Trend Anal Chem 27 904-915... 

Kajiwara, N., Ueno, D., Ramu, K., Kamikawa, S., Yamada, T., Chung, K.H., Tanabe, S., 2004. Geographical distribution and temporal trends of polybrominated diphenyl ethers (PBDEs) in cetacean from Asian waters. The third international workshop on bromin-ated flame retardants. June 6-9, 2004. Canada, pp. 187-190. 

With all the changes underway for flame-retardant technology, sustainability requirements for polymeric materials, and ever-changing fire risk scenarios, it can be quite hard to predict what the future of flame retardancy will be, but there are some trends and information that allow us to make some suggestions about the future. So, our predictions for the future are the following ... 

Halogen-based flame retardants have served a great need for effective flame retardancy for several years. Due to relatively recent environmental concerns, there is a continuing trend toward the development of nonhalogenated materials to replace these systems. While this has been underway for quite some time, it does not appear that nonhalogenated materials will be available in the near future. Hence it appears that there is still a need for these materials to prevent fires. 

This chapter has provided a concise account of an important type of flame retardants based on silicon. This class of flame retardants may provide an opportunity to develop systems for fire retardancy that are environmentally friendly. It seems that there is a growing interest in this type of flame retardant, and this trend most likely will continue, given the increasing concern over the release of the halogenated species into the environment. 

Morgan, A. B. and Wilkie, C. A. Practical issues and future trends of polymer nanocomposite flammability research, in Flame Retardant Polymer Nanocomposites, Morgan, A. B. and Wilkie, C. A. (Eds.) John Wiley Sons Hoboken, NJ, 2007, p. 421. 

Incorporation of modified clays into thermosetting resins, and particularly in epoxy35 or unsaturated polyester resins, in order to improve thermal stability or flame retardancy, has been reported.36 A thermogravimetric study of polyester-clay nanocomposites has shown that addition of nanoclays lowers the decomposition temperature and thermal stability of a standard resin up to 600°C. But, above this temperature, the trend is reversed in a region where a charring residue is formed. Char formation seems not as important as compared with other polymer-clay nanocomposite structures. Nazare et al.37 have studied the combination of APP and ammonium-modified MMT (Cloisite 10A, 15A, 25A, and 30B). The diluent used for polyester resin was methyl methacrylate (MMA). The... 

Emerging chemical regulation, such as REACH, is focusing on the need for characterizing all chemical substances in use in terms of their environmental and human health impacts. This basic tenet of no data—no market will set the trend for regulations to be implemented in other parts of the world. The development of such information should allow sound, science-based decisions to be made about chemicals, their use, and, where necessary, substitution strategies. For the producers and down stream users of chemicals, there will be new opportunities for innovation, but within a more stable business environment than we have had in the recent past. This has to be positive for flame-retardants as well as for other chemicals. 

New trends involve the use of nanoparticles in synthetic fibers. Polymer-layered silicates, nanotubes, and POSS have been successfully introduced in a number of textile fibers, mainly poly-amide-6, polypropylene, and polyester. Although they reduce the flammability of these fibers, but on their own are not effective enough to confer flame retardancy to a specified level. However, in presence of small amounts of selected conventional FRs (5-10 wt %), synergistic effect can be achieved. With this approach fibers having multifunctional properties can also be obtained, e.g., water repellency or antistatic properties along with fire retardancy. Most of the work in this area at present is on the lab scale and there is a potential to take this forward to a commercial scale. 

Modesti, M. Lorenzetti, A. Recent trends in flame retardancy of polyurethane foams. In Progress in Polymer Degradation and Stability Research, Moeller, H.W., Ed. Nova Science Publisher New York, 2008 pp. 115-148. 

After PVC, polyolefin copolymers, predominantly polyethylene copolymers, are the next most widely used material for FR applications in wire and cable. Polyethylenes have very good dielectric strength, volume resistivity, mechanical strength, low temperature flexibility, and water resistance. In contrast to PVC, polyolefins are not inherently FR and thus are more highly formulated, requiring the addition of FRs to meet market requirements for flame retardancy. For this reason, and because of the steady global trend toward halogen-free materials for wire and cable applications, more space will be devoted to this section on FR polyolefins compared with the above discussion of PVC. 

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