Improving the fire resistance of semi-rigid polyurethane foams with cellulose-based layer coatings


Guliyev R., TEKİN N., BORA M. Ö., Yagci Y. E.

CELLULOSE, 2026 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1007/s10570-026-06986-5
  • Dergi Adı: CELLULOSE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Compendex
  • Kocaeli Üniversitesi Adresli: Evet

Özet

Some halogen-phosphorus-based flame retardants (FR), commonly used to improve the fire resistance of polyurethane (PU) foams, have been banned or restricted due to high toxicity and potential carcinogenicity. As a result, research has shifted toward sustainable, low-cost, and environmentally friendly alternatives. This study explores the application of pure cellulose sulfate (CS) and chitosan (CH) compounds onto semi-rigid polyurethane foam (SrPUF) surfaces using a layer-by-layer (LbL) coating method. Coatings were applied in three (3 BL) and six (6 BL) bilayers. Surface chemical characterization was confirmed using Fourier Transform Infrared Spectroscopy (FTIR). The flame-retardant performance of the CS/CH-coated SrPUF was evaluated. A six-bilayer coating increased the Limiting Oxygen Index (LOI) from 17 to 29%. In addition, the peak heat release rate decreased by 43.03%, CO2 emission by 79.57%, and CO emission by 67.69%. The 6 BL-coated SrPUF achieved a V-0 rating in the UL 94 vertical combustion test. During horizontal combustion tests with temperatures up to 1300 degrees C under torch flame, the coated samples showed immediate self-extinguishing behavior. These results indicate that CS/CH coatings are promising as safe, effective, and sustainable flame-retardant alternatives for SrPUF, particularly for applications in the automotive industry.