Science cites campus’s work on fire-retardant polymers

Campus chemical engineers and polymer scientists are collaborating with two other institutions to invent new fire-proof fabrics for military clothing that will save lives by coolly standing up to temperatures reaching 400 degrees Celsius.

In October, their work made the highly selective “Editor’s Choice” highlights in Science. The Science selection dealt with fire-retardant siloxane polymers made with enzyme catalysis. These polymers were created for the U.S. Army as the potential stuff of military clothing and accessories, not to mention dreams. “Fire-retardant fabrics are way up there on their wish list,” says team member Phillip Westmoreland, head of Chemical Engineering.

The research was done by a group from UMass Amherst and UMass Lowell for the Army’s Soldier Systems Center in Natick. The Oct. 15 edition of Science cited the team’s article in the Sept. 3 issue of Advanced Materials, entitled “Biocatalytic Synthesis of Highly Flame-Retardant Inorganic-Organic Hybrid Polymers.”

Specifically, the group has been using enzymes as catalysts that create environmentally clean, stable, inexpensive, and very fire-resistant polymers, based on specific siloxanes that have mixed organic and inorganic backbones. “The work has a ‘green chemistry’ aspect,” says Westmoreland. “There are no harsh solvents, and it’s an environmentally safe way to produce things.”

For their part, Westmoreland and Chemical Engineering Ph.D. student Aur?lie Schoemann used new instrumentation and methods developed on campus to determine not only how flammable a material is, but also to pinpoint what chemical factors make it fire-resistant. When used at the early stages of polymer development, this combination rapidly determines how best to proceed. It indicated excellent flame resistance in the present work.

The ultimate goal of this research is saving human life and limb, and it’s part of a larger program on campus that’s been synthesizing fire-retardant polymers for more than a decade. Much of that larger body of work has been aimed at making a quantum leap in the fire-resistant characteristics of materials for aircraft interiors. “What we’d like to do with airplane crashes,” says Westmoreland, “is eliminate the 25 percent of deaths that are due to fire and smoke. In designing polymers for this purpose, you would like to have either no gases when the materials decompose, or gases that don’t burn. That’s the strategy.”

Some of these new materials promise to make airplane interiors fire-resistant enough to meet a recent Congressional mandate, which gives airplane manufacturers until 2007 to lengthen the average escape time in burning aircraft from the current four minutes to 15 minutes. If American Airlines Flight 1420 had been blessed with such material when it crash-landed at Little Rock National Airport in June of 1999, the 10 passengers and crew who died from fire and smoke inhalation might have been saved.

The lead author of the Advanced Materials article was Rajesh Kumar of UMass Lowell, and other co-authors were Rahul Tyagi, Jayant Kumar, and A.C. Watterson of UMass Lowell, Virinder Parmar of the University of Delhi, Lynne Samuelson of the Natick Soldier Center, and Schoemann and Westmoreland.