The objective of this project is to evaluate the performance in extreme environments of a new class of self-intumescent compounds which have both flame retardant and foaming agent properties. These new compounds, generally referred to as PNS-F*, are formed by reaction of an ethyleneamine with an ethoxylated fatty alcohol phosphate ester. As there exists a range of ethyleneamines and ethoxylated fatty alcohols, a family of PNS-F compounds can be synthesized and evaluated. The project team will test the hypothesis that by varying the fatty alcohol and the ethyleneamine used for composition, the properties of PNS-F in extreme environments can vary.

*PNS-F: Molecular variant of Diethylenetriamine Polyphosphate (PNS). Both PNS and PNS-F have fire extinguishing properties, PNS-F also has foaming properties.

Technical Approach

The technical approaches of this project will be fourfold:

a. Optimize the best choice of ethyleneamine, fatty alcohol, the molecular weight of polyphosphate and the degree of ethoxylation.

b. Characterize the properties of these new compounds. This will be an iterative process. The project team will begin by screening with a few fundamental properties. Selected compounds may be evaluated for a wider range of testing. The aim with the testing is to determine which properties best predict fire performance.

c. Evaluate the best performing compounds in extremes of temperature and when used with different fuels and salt water in small scale testing at 1ft2.

d. Evaluate the best performing compounds in extremes of temperature and when used with different fuels and salt water in large scale testing at 28ft2.


The military desires a fluorine free foam that can pass MIL-PRF-24385. There are many fluorine free (FF) foams commercially available but none can pass this stringent test. While foam manufacturers do not disclose their formulations, it is suspected that most of these FF foams have similar ingredients which have been in use for many years. The project team has developed a novel class of fire extinguishing agents which have shown promise in small scale testing. PNS-F refers to a group of self-intumescent, fire extinguishing compounds which are also foaming agents. The goal of this project is to further develop and refine these compounds such that a FF foam can be created that passes MIL-PRF-24385 and is effective over a range of extreme conditions.

Additionally, this work seeks to answer whether fundamental measurements can instruct the selection of ingredients in a best performing FF foam. One of the barriers to formulating new FF foams is that there is little information as to how the performance of ingredients in FF foams correlates with physical measurements of the foam because most foam formulations are proprietary and the ingredients are unknown. This research study will test hundreds of foam compositions by the 1ft2 fuel fire test. As the project team refines and fire tests different molecular forms of PNS-F and foam formulations, a selection of the samples for testing of physical properties will be submitted to a laboratory at the Navel Research Labs . In this way, important information regarding the physical properties, performance and composition can be compiled.