Layer-by-layer polymer deposited fabrics with superior flame retardancy and electrical conductivity

Abstract

Smart and multifunctional textiles and fabrics are progressively developing, such that multifunctional fabrics are becoming more widespread. We elaborated herein multi-layered flax fabrics with superior flame retardancy and conductivity, which revealed fireproof feature while keeping conductivity during burning. The flax fabric was reinforced by layer-by-layer (LbL) deposition of sodium polyacrylate (SPA), polyethylenimine (PEI), ammonium polyphosphate (APP), and lastly a composite having poly(aniline-co-melamine) and montmorillonite (MMT) coated the aforementioned layers. The resulting multi-layered fabrics were characterized systematically by Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and thermogravimetric analysis (TGA). Flame retardancy of fabrics was conducted on pyrolysis-combustion flow calorimetry (PCFC), and a vertical burning test. TGA test showed a significant increase in the amount of residue of the treated fabrics (37%) against 19% assigned to untreated flax fabrics. Surprisingly, PCFC showed a very low peak of heat release rate (pHRR) of 15 W/g (HRR) for reinforced flax fabrics with respect to 234 W/g assigned to untreated flax fabrics (≈ −94%). In addition, the vertical burning test demonstrated the fireproof character of multi-layered fabrics. The conductivity of coated flax fabric was in the range of 1–8 × 10−7 S/cm before burning, which astonishingly survived up to 30 s after burning. This bi-functional flame retardant and conductive fabric enables taking next steps towards development of fireproof conductive materials for advanced technologies.