Flame retardant nanocoatings for foam and fabric made with renewable and/or environmentally-benign materials
- Additional Document Info
- View All
Here we describe antiflammable nanocoatings deposited onto foam and fabric using layer-bylayer (LbL) assembly. LbL deposition involves exposing a substrate (e.g., plastic film, fabric, glass, etc.) to solutions of oppositely charged ingredients. Each anionic (e.g., clay) and cationic (e.g., chitosan) layer is 1 - 100 nm thick depending on a variety of deposition conditions. We are producing assemblies that are very conformal and able to impart flame resistance to foam and fabric. In the case of cotton fabric, each 10 μm fiber is individually coated to create a thermal shield. On foam, a 4 wt% nanocoating can cut the heat release rate (HRR) in half, relative to uncoated foam, and eliminate melt dripping during direct exposure to a propane torch for 10 seconds. When the foam was cut open, there was untouched white foam under a relatively thin black char layer made primarily of clay. This environmentally-friendly flame retardant could be used to protect nearly any type of substrate. By treating cotton fabric with intumescent nanocoatings, composed of poly(ally amine) and poly (sodium phosphate), no ignition occurs during UL-94 testing (i.e., the fabric did not burn when exposed to direct flame). All of the materials described are water-based and processing occurs under ambient conditions.
author list (cited authors)
Laufer, G., Li, Y. C., & Grunlan, J. C.