Polymeric materials, combustion

The analysis of these materials is even more critical with increased interest in their environmental impact on ecological systems and human health. A number of frequently used additives, such as phthalate and adipate plasticizers have been identified as environmental pollutants, and the fate of these chemicals is the subject of ongoing studies. Concern over the total composition of plastics has increased the focus on the total life cycle of polymeric materials. Government attention to toxic substances has increased over the years through the US Toxic Substances Control Act (TSCA) and the REACH initiative in the EU. These regulations may prohibit or otherwise impact the exportability of the plastic goods or other products that come in contact with the plastics. This, coupled with increased consumer attention and disclosures of chemicals in consumer products, has increased the need for a more complete analysis of polymeric materials. Combustion of rubber... 

R. M. Aseeva and G. E. Zaikov, Combustion of Polymeric Materials, Hanser Pubhshers, Munich and New York (dist. in the United States by Macmillan) 1985, pp. 229-241. 

The limiting oxygen index of Tefzel as measured by the candle test (ASTM D2863) is 30%. Tefzel is rated 94 V-0 by Underwriters Laboratories, Inc., in their burning test classification for polymeric materials. As a fuel, it has a comparatively low rating. Its heat of combustion is 13.7 MJ/kg (32,500 kcal/kg) compared to 14.9 MJ /kg (35,000 kcal/kg) for poly(vinyHdene fluoride) and 46.5 MJ /kg (110,000 kcal/kg) for polyethylene. 

Most fires involve the combustion of polymeric materials. Despite the involvement of polymers in fires, there have been no books on current research topics in this area of fire research in some years. Given the importance of fire and polymers as a social issue and the complexity and interest in the relevant basic science, Eli Pearce of Polytechnic University of New York and I cochaired a one-week symposium on fire and polymers. It was the first major symposium held on fire and polymers at an American Chemical Society National Meeting in about five years. 

Tewarson, A., "Physicochemical and Combustion Pyrolysis Propel— ties of Polymeric Materials," 1980, National Institute of Standards and Technology, Gaithersburg, MD, Technical Report NBS-GCR-80-295. 

Nitramine composite propellants composed of HMX or RDX particles and polymeric materials offer the advantages of low flame temperature and low molecular mass combustion products, as well as reduced infrared emissions. The reduced infrared emissions result from the elimination of COj and H2O from the combustion products. To formulate these composite propellants, crystalline nitramine monopropellants such as HMX or RDX are mixed with a polymeric binder. Since both HMX and RDX are stoichiometrically balanced, the polymeric binder acts as a coolant, producing low-temperature, fuel-rich combustion products. This is in contrast to AP composite propellants, in which the binder surrounding the AP particles acts as a fuel to produce high-temperature combustion products. 

I 5 Combustion of Crystalline and Polymeric Materials CHjO + NOj CH2O2 + NO... 

Aluminum (Al) is a silver-colored light and soft metal used as a major component of aluminum alloys, which are used to construct aircraft and vehicles, similar to Mg alloys. However, Al is known as a readily combustible metal. Thus, Al particles are used as major fuel components of pyrolants. Al particles are mixed with ammonium perchlorate particles and polymeric materials to form solid propellants and underwater explosives. The reaction between aluminum powder and iron oxide is known as a high-temperature gasless reaction and is represented by ... 

When AN powder is mixed with a polymeric material, the oxygen gas produced by the decomposition of the AN powder reacts with the hydrocarbon fragments of the thermally decomposed polymeric material. The major combustion products are GO2 and H2O. Nitropolymers are not used as fuel components of AN pyrolants because of the reaction between the NO2 formed by their decomposition and the AN powder. This reaction occurs very slowly and damages the physical structure of the AN pyrolant. Instead, polymeric materials containing relatively high mass fractions... 

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