TOXICITY AND THERMAL PROPERTIES OF POLYPHOSPHAZENES

Flammability and toxicity of nine polyphosphazene copolymers, with and without fillers, were measured and compared with other more conventional plastics of commercial interest (polyethylene and polytetrafluoroethylene). First reports on limiting oxygen index (LOI), determined as a function of heat flux, and toxicity monitoring under isothermal and nonisothermal conditions are provided for these polymers. 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 influence LOI measurements. Foam samples burn more readily than films of the same chemical composition. RD50 (concentration which induces a 50% decrease in respiratory rate in mice) and LC50 (concentration where 50% mortality occurs) values were obtained by exposing mice to a gaseous stream of polyphosphazene decomposition products. The respiratory response of the animals is directly correlated with the rate of polymer decomposition. The toxicity of a particular polyphosphazene depends strongly upon the type of the side groups on the phosphorus. Halogen side groups result in the most toxic products. There is no direct correlation between toxicity hazard and carbon monoxide concentration in these polymers. The respiratory depression is more severe under isothermal heating (below ignition) than under programmed linear heating. Based on an overall hazard rating involving thermal stability, flammability, and toxicity parameters, halogen free polyphosphazenes are favored over halogen containing polymers for high temperature applications.

• Corporate Authors:

  Technomic Publishing Company, Incorporated

  265 Post Road West
  Westport, CT  United States  06880
• Authors:
  • Lieu, P J
  • Magill, J H
  • Alarie, Y C
• Publication Date: 1980-7

Media Info

• Features: References;
• Pagination: p. 167-183
• Serial:
  • Journal of Fire & Flammability
  • Volume: 11
  • Publisher: Technomic Publishing Company, Incorporated

Subject/Index Terms

• TRT Terms: Copolymers; Flammability; Halogens; Hazards; Plastics; Thermal properties; Toxicity
• Old TRIS Terms: Limiting oxygen index; Polyphosphazenes
• Subject Areas: Safety and Human Factors;

Filing Info

• Accession Number: 00379100
• Record Type: Publication
• Source Agency: National Highway Traffic Safety Administration
• Report/Paper Numbers: HS-030 158
• Contract Numbers: NONR-356-644
• Files: HSL, USDOT
• Created Date: Oct 30 1983 12:00AM