Non-Halogenated Polymer Flame Retardant

Case ID:

This invention is a flame retardant composition comprising a sulfur copolymer prepared from elemental sulfur using inverse vulcanization. These polymers may be copolymerized with a wide variety of other monomers. When exposed to combustion temperatures, they form high char content, self-extinguishing materials. These polymers may be prepared in blends for application as non halogenated coatings to substrates requiring fire retardant protection. 


Synthetic polymers are often highly flammable and may not meet fire safety standards on their own. Polymers, such as the polyurethane foams typically found in airplane seats or other furniture cushions, polymers used in electrical applications or for personal protective equipment (PPE), must be treated to be flame retardant. Common flame retardant chemicals are based on halogenated compounds and many of them have been banned due to concerns over their potential toxicity. There is a need for less toxic chemicals for imparting flame retardant properties which meet national and international standards for performance.


  • The sulfur-based polymer is made from elemental sulfur, a low-cost byproduct or waste material available in large quantities from petroleum refining
  • No halogenated material is used
  • The material has been shown to have higher char yields than other synthetic polymers, thereby exhibiting potentially improved performance as a flame retardant


  • Personal protective equipment and other fabrics
  • Electrical equipment
  • Foams used for airplanes, hotels, furniture

Status: issued U.S. patent #11,015,023

For related flame retardant polymer technologies, see

Patent Information:
Contact For More Information:
Jonathan Larson
Senior Licensing Manager, College of Science
The University of Arizona
Lead Inventor(s):
Dong-Chul Pyun