Demonstrate the use of polyethylene oxide based polymers as a suitable replacement for per- and polyfluorinated alkyl substances (PFAS) in aqueous film forming foams (AFFF). The technical approach addresses the primary objective in WPSON-20-A1. This project will result in:

1. the development of polyethylene oxide-based polymers as a suitable drop-in replacement for existing applications of AFFF,
2. use of suitable laboratory scale testing to evaluate foam properties, foam degradation, fuel transport through a foam layer, and extinction performance in a 19 centimeter (cm) pool fire, and
3. full scale testing under MIL-PRF-24385F including 28 feet squared (ft²) pool fire testing at the Naval Research Laboratory (NRL) Chesapeake Bay Detachment (CBD) fire test facility located in Chesapeake Beach, MD.

The project work incorporates synthesis and characterization of polyethylene oxide-based polymers for the purposes of developing a fluorine-free AFFF formulation suitable as a drop-in replacement for existing AFFF. This work is broken down into three tasks: 1) Synthesis and characterization of polyethylene oxide (PEO)-based AFFF polymers, 2) laboratory-based evaluation of synthesized polymers, and 3) MIL-PRF-24385F testing of PEO formulations at the NRL CBD fire testing facility. Specifically, the traditionally hydrophilic PEO will be chemically modified to incorporate hydrophobic/oleophilic groups in order to make these polymers suitable for use in AFFF formulations. A Dynamic Foam analyzer will be used to determine foam properties such as drainage rate and bubble size, followed by mechanistic testing associated with foam fire suppression. In this instance, the research team will evaluate foam degradation and fuel transport – how long the foam maintains coverage on a pool and how fuel transports through the foam layer. These laboratory-based experiments conclude with a 19 cm pool fire test. Finally, PEO formulations will be evaluated using parameters described in MIL-PRF-24385F including 28 ft² pool fire testing and a number of select chemical and physical property tests including corrosion testing, COD & BOD testing, and PFOS & PFOA analysis.

The development of a drop-in fluorine-free replacement for existing AFFF formulations is highly desirable. PEO-based formulations will provide a low toxicity drop in replacement that is made from commonly available polymer material which provides easier scale up and reduced costs.