Durable flame retardant and dip-resistant coating of polyester fabrics by plasma surface treatment and UV-curing

Polyester fabric is ubiquitously applied for clothing, furniture and transportation, whereas its flammability with severe dripping often causes secondary hazards. Herein, it is highly imperative to impart excellent flame retardant to polyester fabric. In this work, a coating for polyester fabrics was prepared through a continuous dipping and ultraviolet (UV) curing process, which exhibited high-efficiency flame-retardant, anti-dripping and washing resistance. Firstly, the surface of polyester fabric was pretreated with plasma for providing more grafting sites of polyester fabric. Then, the flame retardant 6-((((2-(acryloyloxy) ethoxy) (oxo)(phenyl)phosphonio) oxy) methyl) dibenzo[c,e][1,2]oxaphosphinine 6-oxide (DPEA) and Tri(acryloyloxyethyl) phosphate (TAEP) were successfully synthesized and applied to the coating by UV-curing. In vertical burn test, the damage length of polyester with DPEA and TAEP (PET-D3/T4.5) was reduced from 300 mm of pristine PET to 100 mm with no dripping. In the Thermogravimetric Analysis (TGA) test, the char residue of PET-D3/T4.5 in nitrogen increased to 26.7 % compared with 9.7 % of pristine polyester. More specifically, the Peak Heat Release Rate (PHRR) and Total Heat Rate (THR) of PET-D3/T4.5 decreased 43.3 % and 22.2 % in the Micro-scale Combustion Calorimetry (MCC) test, which reflected excellent thermal stability and flame retardant properties. In addition, the Limiting Oxygen Index (LOI) of PET-D3/T4.5 only dripped from 24 % to 23.5 % after ten standard laundering cycles, indicating prominent water resistance. Remarkably, Thermogravimetric Analysis-Fourier transform infrared (TG-IR), Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS) have been performed for investigating the mechanism of flame retardant. Thus, a strategy with convenience and economics is proposed, which is of gargantuan significance to the improvement of coating durability through plasma surface treatment and UV-curing.