Toxicity and Thermal Properties of Polyphosphazenes.
Abstract
Flammability and toxicity of various polyphosphazenes with and without fillers have been measured. The performance characteristics of these polymers are compared with other more conventional plastics of commercial interest. Other small scale tests such as limiting oxygen index, at different heat fluxes, have been used as indicators of flammability. Under ambient conditions, polyphosphazenes require a higher oxygen concentration to burn than air alone can supply. LOI values always decrease as heat flux or ambient temperature is raised. Fillers also influence LOI measurements. Foam samples burn more readily than films of the same chemical constitution. RD(50) and LC(50) values were obtained by exposing animals (mice) to a gaseous stream of polyphosphazene decomposition products. The respiratory response of mice is directly correlatable with the rate of polymer decomposition. The toxicity of a particular polyphosphazene depends strongly upon the type of the side groups on the phosphorus. There is no direct correlation between toxicity hazard and CO concentration in these polymers. Halogen side groups give rise to the most toxic products. Based upon an overall hazard rating involving thermal stability, flammability and toxicity parameters, halogen free polyphosphazenes are favored over halogen containing polymers for high temperature applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 19, 1979
- Accession Number
- ADA072120
Entities
People
- J. H. Magill
- P. J. Lieu
- Y. C. Alarie
Organizations
- University of Pittsburgh