Highly Flame Retardant Expanded Polystyrene Foams from Phosphorus–Nitrogen–Silicon Synergistic Adhesives

Abstract

Three novel, environmentally friendly, flame-retardant adhesives (FRAs), i.e., (1) poly-N-β-(aminoethyl)-γaminopropyltrimethoxysilane [P(NTMS)], (2) P(NTMS-phosphoric acid) [P(NTMS-PA)], and (3) P(NTMS-phosphorous acid) [P(NTMS-POA)], are synthesized via a versatile sol−gel method. The chemical structures are characterized by FTIR and 1 H NMR. The thermal stabilities of the FRAs are revealed by thermogravimetric analysis (TGA) and they exhibit single, double, and triple degradation processes, respectively. Flame-retardant expanded polystyrene foams (EPSFs) are prepared with these novel environmentally friendly FRAs by a simple coating method, and their flammability is investigated by limiting oxygen index (LOI), UL-94 vertical burning test, and cone calorimeter (CC). With as high as 57 wt % of P(NTMS) coating, the foam gains no rating in the UL-94 test. In contrast, EPSF with 57 wt % of P(NTMS-PA) coating passes the UL-94 V-0 grade with a LOI of 31%, and the foam with only 40 wt % of P(NTMS-POA) also passes the UL-94 V-0 grade with a LOI of 26.5%. CC results demonstrate that 40 wt % of P(NTMS-PA) coating reduced the peak heat release rate (PHRR) of EPSF by 62.1% and increased the residue from 0 to 36.2%. For P(NTMS-POA), the corresponding values are 68.8% and 34.0%, respectively. The morphology of the residues was revealed by SEM, and the corresponding chemical compositions and carbonaceous structure were studied by FTIR, EDX, and Raman spectra. These results indicated a synergy in charring among phosphorus, nitrogen, and silicon, and the resulting protective layers were responsible for the higher fire safety.

Synthesis and Characterization of Paraffin/Metal Organic Gel Derived Porous Carbon/Boron Nitride Composite Phase Change Materials for Thermal Energy Storage

“…The thermal stability of the composites was measured using TGA test (Figure and S3). The degradation temperature T 5 % , upon which 5 % of the sample weight is lost, indicates vital information about the stability of the samples , . As shown in Figure a, the pristine BN shows a superb thermal stability (no weight degradation up to 1000 °C) unlike cMOG shows a T 5 % at 259 °C (Figure b) possibly due to some impurities.…”

Lightweight, Elastomeric, and Flame‐Retardant Foams from Expanded Chlorinated Polymers

“…From Figure , it is observed that the LOI for CC_60/40 foam (35%) was 1.7 times the oxygen level in the air (20.9%). This value is significantly higher than that measured for the pristine CPE foam (24%), as well as other polymeric foams such as PU, PS, and polymethacrylimide foams (typically 20–30) . Furthermore, cone calorimetry was performed to assess the combustion behavior of the foams.…”

A novel intumescent flame retardant imparts high flame retardancy to epoxy resin

“…As seen in Table , by comparison with EP and EP‐5, EP‐7 had the lowest FIGURERA value. As well‐known that the lowering of FIGURERA meant a reduction in flame spread, which increased escape time in real life fire scenarios …”