Layer-by-Layer (LbL) assembled multilayer thin films of deoxyribonucleic acid (DNA), chitosan (CHI), and montmorillonite (MMT), were studied in an effort to produce fully renewable, bio-based fire retardant coatings for flexible polyurethane foam. The PUF bio-coatings constructed of 10 bilayers of CHI/DNA+MMT (16.2 % mass), 10 trilayers of CHI/MMT/DNA (8.1 % mass), and 5 quadlayers of CHI/DNA/CHI/MMT (4.9 % mass) all resulted in a significant reduction in critical flammability metrics, peak heat release rate (pHRR) and average HRR (aHRR). The mix bilayer, CHI/DNA+MMT, is the best formulation as it resulted in the greatest flammability reduction (51% pHRR and 81% aHRR) with the fastest bio-coating growth and the least amount of preparation and waste. This DNA and MMT- based bio-coating is the greatest flammability reduction of PUF reported to date using the LbL process. Constructed of bio-based and non-toxic materials combined with the fast growing BL approach, which has minimal waste, this is presumably the most environmental and bio-friendly fire retardant LbL coating reported.
Citation: Green Materials
Pub Type: Journals
DNA, renewable materials, Layer-by-Layer assembly, polyurethane foam, flame retardant, cone calorimetry, furniture