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ABSTRACTS AND R E V I E W S 251 C2H2-F2 The main products of this flame are H F and CFj CFj recombines to C2F4 when the burnt gas is cooled The nature of the intermediates indicates that addition reactions of F and F2 to unsaturated hydrocarbons and their radicals, respectively, are important The formation of soot in this flame is compared to that in an acetylene-oxygen flame C2H4-F2 Since a large amount of C2H4 is decomposed to C2H2 m pnmary reactions, the concentration profiles in this flame are very similar to those in an C2H2-F2 flames Lipska, A. E . (Stanford Research Institute, Menlo Park, Califorma) "The Fire-Retardance Effectiveness of High-Molecular-Weight, High-Oxygen-Con- taining Inorgamc Additives in Cellulosic and Synthetic Materials," Annual Report to Defense Civil Preparedness Agency under Contract No DAHC20-70-C- 0219 (August 1972) Sections: H, A Subjects: High-molecular-weight inorganic additives; Permanent flame retardants. Cotton, Rayon, Roofing matenal, Nylon; Polyester, Cellulosic materials, Phosphomolybdic acid; Phosphotungstic acid; Ammonium phosphotung- state; Flaming igmtion, Decomposition products. Char, Isothermal pyrolysis of cotton, Kinetics of decomposition Author's abstract A feasibility study was conducted to determine whether high-molecular-weight inorganic additives, particularly those with high oxygen content, can be used effectively as permanent flame retardants for cotton, rayon, roofing material, nylon, and polyester Results show that cellulosic matenals treated vÌith either phosphomolybdic acid, phosphotungstic acid, or ammonium phosphotungstate do not sustain flaming Igmtion when exposed to an irradiance of 6 2 cal cm-* sec-' from a CO2 laser for 6 3 seconds Furthermore, the retardant treatment caused a drastic change in the decomposition products of the materials and mcreased the yields of char Cedar shakes treated with either phosphotungstic acid or its insoluble am- monium salt required 65 seconds of exposure to a Fisher burner for ignition, whereas 4 seconds of exposure caused igmtion m untreated shakes Moreover, the treated specimens ceased flaming after they were removed from the Fisher flame and the untreated shakes continued to bum even when they were removed from the igni- tion source More extensive evaluation of the efficiency of these treatments and of our tech- nique is needed to substantiate our present findings For example, the procedure used to incorporate the phosphotungstic acid and its salt into nylon and polyester must be modified before the optimal loading and efficiency of the retardant can be achieved
