Polyelectrolyte Complex with Controllable Viscosity by Doping Cu²⁺ Protects Nylon–Cotton Fabric against Fire

Abstract

Nylon–cotton (NC) blend fabrics are widely used in military and industrial applications, but their high flammability still remains a serious problem. In an effort to effectively and quickly impart flame retardancy to the NC fabric, it was treated by simply blade coating with a Cu2+-doped polyelectrolyte complex (CPEC) that consists of ammonium polyphosphate (APP), polyethylenimine (PEI), and copper sulfate. The viscosity of the CPEC can be adjusted by altering the content of CuSO4, which controls the amount of extrinsic and intrinsic ion pairs. By adjusting the proportion and content of PEI, APP, and CuSO4, CPEC suitable for treating the NC fabric was obtained. Only 0.067 wt % Cu2+ was needed to adjust the viscosity and impart self-extinguishing behavior in a vertical burning test. This simple two-step treatment provides a promising technology to protect flammable polymeric substrates with ultralow metal-doped polyelectrolyte complexes.

Phosphate and nitrogen‐rich polyelectrolyte complex flame retardant treatment for cotton fleece

“…Removal of debris or loose fibers from washing and brushing results in small weight changes for the control fleece. Deposition of PEC adds 12.5% weight to the fleece, which is comparable to or lower than other flame retardant surface treatments for textiles 5–8,16–18,25,26 . Conditioning affects coated fleece differently.…”

“…Deposition of PEC adds 12.5% weight to the fleece, which is comparable to or lower than other flame retardant surface treatments for textiles. [5][6][7][8][16][17][18]25,26 Conditioning affects coated fleece differently. As previously observed with this PEC, no appreciable weight change was observed after washing in ionic detergent.…”

“…Previously, water‐based polyelectrolyte complexes (PECs) have been deposited on various textiles for fire protection 5,16–18 . PECs are entropy‐driven associations of oppositely‐charged polyelectrolytes, whose complexation is determined by concentration, ionic strength, and solution pH.…”

“…Previously, water-based polyelectrolyte complexes (PECs) have been deposited on various textiles for fire protection. 5,[16][17][18] PECs are entropy-driven associations of oppositely-charged polyelectrolytes, whose complexation is determined by concentration, ionic strength, and solution pH. PECs can be deposited in a few steps, imparting flame retardancy, gas barrier, or antibacterial properties to a material.…”

Eco-Friendly and Facile Integrated Intumescent Polyelectrolyte Complex Coating with Universal Flame Retardancy and Smoke Suppression for Cotton and its Blending Fabrics

“…Recently, an oppositely charged polyelectrolyte complex (PEC) was deposited on fabrics to simplify the coating processes. − First, PEC with an appropriate pH and concentration was water-soluble and could be deposited on the fabrics via immersion. , Then, the PEC-coated fabric was subjected to a buffer solution to produce an insoluble PEC coating, which is called “curing” . Notably, PEC coatings with the ability to form intumescent char manifest great potential in suppressing flame propagation and reducing the production of heat and smoke in fabrics .…”