Controlled Architecture of Polyhedral Oligomeric Silsesquioxane-Functionalized Poly(Glycidyl Methacrylate)/Polyester Composites Using Surface-Initiated ICAR ATRP Technique for High Flame Retardancy and Smoke Suppression

Ti3C2Tx MXene-based hybrid nanocoating for flame retardant, early fire-warning and piezoresistive tension sensing smart polyester fabrics

Flammability feature of textiles is a big underlying risk causing fire disasters. The fabrication of reliable fire resistant and quick fire warning fabrics is imperative but challenging. Herein, three types of early fire-warning polyester fabrics, namely, FPP@AM-X, FPP@PM-X and FPP@AX-M1, with good flame retardant and piezoresistive sensing performance were developed by fabricating polyethyleneimine (PEI), ammonium polyphosphate (APP), phytic acid (PA) and MXenes onto phosphorus-containing flame retardant polyethylene terephthalate (FRPET) via polydopamine (PDA) mediated layer-by-layer self-assembly. Owing to the improved thermoelectric properties of MXenes, FPP@A5-M1 exhibited a maximum thermoelectric voltage of 0.59 mV at a temperature difference of 130 °C and can provide an ideal cyclic early fire warning response within 4 s. In addition, due to the synergistic flame retardant effect of MXenes and APP in the coating layer, FPP@A5-M1 could be self-extinguished within 2 s after ignition and the value of peak heat release ratio and total smoke production decreased by 41.9% and 30.4%, respectively. Besides, the MXene-based hybrid coated fabric can detect the movement of human fingers and elbows, illustrating its potential application in piezoresistive tension sensing. This work provides a new route to designing and developing multi-functional and smart fire protection fabrics.

Synthesis and Characterization of a Novel DOPO-Based Flame Retardant Intermediate and Its Flame Retardancy as a Polystyrene Intrinsic Flame Retardant

The research on intrinsic flame retardant has become a hot topic in the field of flame retardant. The synthesis of reactive flame-retardant monomer is one of the effective methods to obtain an intrinsic flame retardant. In addition, in view of the small molecular flame retardant easily migrates from the polymer during the use process, which leads to the gradual reduction of the flame retardant effect and even the gradual loss of flame retardant performance, and the advantages of atom transfer radical polymerization (ATRP) technology in polymer structure design and function customization, we first synthesized reactive flame retardant monomer 6-(hydroxymethyl)dibenzo[c,e][1,2]oxaphosphinine 6-oxide (FAA-DOPO), then synthesized polystyrene bromine (PS148-Br) macromolecular initiator by ATRP technology, and finally obtained block copolymer polystyrene-b-poly{6-(hydroxymethyl)dibenzo[c,e][1,2]oxaphosphinine 6-oxide} (PS-b-PFAA-DOPO) by the polymerization of FAA-DOPO initiated by macromolecular initiator PS148-Br by ATRP technology. The chemical structure of FAA-DOPO was characterized by 1D and 2D NMR (1H, 13C, DEPT 135, HSQC, COSY, NOE, and HMBC) spectra, Fourier transform infrared spectroscopy (FTIR), liquid chromatography-tandem mass spectrometry (LC-MS) and X-ray photoelectron spectroscopy (XPS). The chemical structure and molecular weight of PS-b-PFAA-DOPO were characterized by FTIR and gel permeation chromatography (GPC). The thermal and flame-retardant properties of PS-b-PFAA-DOPO were characterized by thermogravimetry analysis (TG), UL-94, limiting oxygen index (LOI), and microscale combustion calorimetry (MCC). It was found that FAA-DOPO could be used as a monomer for polymerization, although FAA-DOPO had a large steric hindrance from the chemical structure of FAA-DOPO, the UL-94 grade of PS-b-PFAA-DOPO reached the V-0 grade, and the LOI increased by 59.12% compared with PS148-Br.