Thermal degradation characteristics of rigid polyurethane foam and the volatile products analysis with TG-FTIR-MS

School of Materials Science and Engineering, North University of China, No. 3 Xueyuan Road, Taiyuan, Shanxi 030051, PR China College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China 3 Integrated Composites Laboratory, Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA Department of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, USA Department of Physics and Engineering, Frostburg State University, Frostburg, Maryland 21532, USA

Flame-retardant rigid polyurethane foam with a phosphorus-nitrogen single intumescent flame retardant

An efficient, environmentally friendly, and water-applied flame retardant surface nanocoating based on polydopamine (PDA) was developed for foamed materials such as polyurethane (PU). The PDA nanocoating, deposited by simple dip-coating in an aqueous dopamine solution, consists of a planar sublayer and a secondary granular layer structure that evolve together, eventually turning into a dense, uniform, and conformal layer on all foam surfaces. In contrast to flexible PU foams that are known to be highly flammable without flame retardant additives, micro combustion calorimetry (MCC) and thermogravimetric analysis (TGA) confirm that the neat PDA is relatively inflammable with a strong tendency to form carbonaceous, porous char that is highly advantageous for flame retardancy. By depositing nanocoatings of PDA onto flexible PU foams, the flammability of the PU foam was significantly reduced with increasing coating thickness. For the thickest coating (3 days of PDA deposition), the foam quickly self-extinguish...

Bioinspired Catecholic Flame Retardant Nanocoating for Flexible Polyurethane Foams

A novel hybridized multifunctional filler (CPBN), cyclotriphosphazene/hexagonal boron nitride (hBN) hybrid, was synthesized by chemically coating hBN with hexachlorocyclotriphosphazene and p-phenylenediamine, its structure was systemically characterized. Besides, CPBN was used to develop new flame retarding bismaleimide/o,o′-diallylbisphenol A (BD) resins with simultaneously high thermal conductivity and thermal stability. The nature of CPBN has a strong influence on the flame behavior of the composites. With the addition of only 5 wt % CPBN to BD resin, the thermal conductivity increases 2 times; meanwhile the flame retardancy of BD resin is remarkably increased, reflected by the increased limited oxygen index, much longer time to ignition, significantly reduced heat release rate. The thermogravimetric kinetics, structures of chars and pyrolysis gases, and cone calorimeter tests were investigated to reveal the unique flame retarding mechanism of CPBN/BD composites. CPBN provides multieffects on improving...

Multifunctional cyclotriphosphazene/hexagonal boron nitride hybrids and their flame retarding bismaleimide resins with high thermal conductivity and thermal stability.

An ammonium salt of ethylene glycol diphosphoric acid (AEGDP) containing nitrogen and phosphorus, a durable and eco-friendly flame retardant for cotton, was synthesized under moderate and solvent-free conditions. The AEGDP structure was characterized by IR, 13C NMR, 1H NMR, and 31P NMR. Thermogravimetry (TG) and TG-infrared (TG-IR) spectroscopy indicate that phosphoric or polyphosphoric acid produced from AEGDP during combustion could catalyze the dehydration of cellulose to form char instead of decomposing it to form volatile flammable species, which include hydrocarbons, some carbonyl compounds, and ethers. The degradation mechanism of cotton fabrics treated with AEGDP was modified because of covalent bonds formed between cotton cellulose and AEGDP. Scanning electron microscopy (SEM) shows that no obvious materials were observed on the surface of the treated cotton, indicating that the –PO(O−NH4+)2 groups of AEGDP may react with the –OH groups of cellulose to form P–O–C covalent bonds and/or penetrate into the inner space of cotton fibers. Vertical flammable tests imply that the control cotton burned completely, whereas the treated cotton showed neither after-flame nor after-glow. The limiting oxygen index (LOI) of cotton treated with 120 g L−1 of AEGDP solution could reach 41.0%, which is significantly higher than that of the control cotton. After 50 laundering cycles, the LOI could be maintained at 28.4%, exhibiting the excellent durability of the treated cotton. Cone calorimetry at 35 and 50 kW m−2 irradiative heat flux reveals that AEGDP causes a reduction in the peak heat release rate and total heat release relative to those of the control cotton. In addition, X-ray diffraction shows that AEGDP fails to substantially change the crystal structure of cotton cellulose. There is no significant change in the bending length of cotton before and after treatment. And the decreased surface tension of the treated cotton is beneficial for its self-cleaning ability.

Facile synthesis of an eco-friendly nitrogen–phosphorus ammonium salt to enhance the durability and flame retardancy of cotton

TG–FTIR characterization of volatile compounds from flame retardant polyurethane foams materials

Flame-retardant polyurethane elastomers (PUEs) have been prepared using trichloroethyl phosphate (TCEP) as flame retardant. The combustion performances and thermal decomposition properties of PUEs ...

Lili Huo

Papers

TG–FTIR characterization of volatile compounds from flame retardant polyurethane foams materials

Combustion properties and pyrolysis kinetics of flame-retardant polyurethane elastomers