DTIC ADA078585: Toxicity of the Degradation Products pdf

DTIC ADA078585: Toxicity of the Degradation Products

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Polyphosphazene copolymers have been degraded under dynamic air flow up to temperatures of 700 degrees C at a heating rate of 35 degree per minute. A few experiments were also conducted up to 1000 degrees C. Animal inhalation screening tests with mice (Swiss Webster) were made under these test conditions. An air flow rate of 20 l/min was employed in the toxicological studies where the temperature in the animal chamber was always held below 45 degrees C, a condition which did not adversely affect the animals under test. Simultaneously, thermogravimetric measurements were made on decomposing polyphosphazenes in order to assess the rate of sample decomposition at different temperatures. Quantitative analytical measurements of the evolution of HCN and CO gases from the polymers (some without fillers) were made under identical thermal and environmental conditions. The results clearly show that there is not a significant correlation between CO-evolved and the induced toxicity in these animals.

A similar conclusion follows for the evolution of HCN gas. Correlation with both these gaseous products indicates that other more lethal products may be responsible for the observed LC50 results. The complexity of the decomposition products has not yet been elucidated, but it has been demonstrated clearly that an animal test model properly applied can be used to screen complex polymeric systems. (Author

• Creator/s: Defense Technical Information Center
• Date: 12/10/1979
• Year: 1979
• Book Topics/Themes: DTIC Archive, Lieu, P J, PITTSBURGH UNIV PA DEPT OF METALLURGICAL AND MATERIALS ENGINEERING, *DEGRADATION, *TOXICITY, *COPOLYMERS, *PHOSPHAZENE, THERMAL PROPERTIES, MODELS, AIR FLOW, RATES, TEST METHODS, GASES, HEATING, ENVIRONMENTAL TESTS, ANIMALS, MICE, DECOMPOSITION, LETHAL DOSAGE, TOXICOLOGY, THERMOGRAVIMETRIC ANALYSIS

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