Mechanism of smoke suppression by melamine in rigid polyurethane foam

Abstract

Summary The smoke suppression of rigid polyurethane foam (RPUF) modified by melamine was investigated based on three sections: the condensed phase, the carbon layer, and the gas phase. In the condensed phase, the results of thermogravimetry, X‐ray photoelectron spectroscopy (XPS) N1S spectrum, and Fourier transform infrared spectroscopy indicated that melamine could suppress the degradation of RPUF by reacting with the aromatic hydrocarbons. It also reduced the smoke generation because the volatilizable aromatic hydrocarbons were the principal smoke precursors in a fire. In the carbon layer, the decrease from 38.50% to 24.76% of the inner layer oxygen content identified by XPS full‐spectrum and C1S spectrum indicated that melamine could prevent oxygen from transferring into the inner foam by the formation of an enhanced surface carbon layer, and the enhanced carbon layer could also block the release of smoke precursors. In the gas phase, the content of total aromatic hydrocarbons declined to 59.12% according to pyrolysis gaseous chromatography mass spectroscopy and indicated that melamine could reduce the smoke precursors. The results of smoke density chamber and cone calorimeter tests revealed that the addition of the melamine could decrease the smoke density of burning RPUF. Copyright © 2014 John Wiley & Sons, Ltd.

Thermal degradation study of pure rigid polyurethane in oxidative and non-oxidative atmospheres

“…In Fig. 4 and aliphatic ethers (1270，1110 cm -1 ) [42], esters (1720 cm -1 ), NO 2 (1754 cm -1 ) etc.…”

A novel and effective method to fabricate flame retardant and smoke suppressed flexible polyurethane foam

“…9 shows the smoke density of pure FPUF, FPUF-1 and FPUF-2 during burning. 39 The smoke production of FPUF contains two parts: the rst part, the thermal degradation products release from the condensed phase into the gas phase by breaking through the carbon layer. The smoke density of pure FPUF becomes stable aer 150 s and the plateau value is about 400, while the FPUF-2 presents a density peak of 305 at 265 s. Aer covered with MH coating, the smoke density of foam signicantly decreases.…”

Polyurethane coatings based on linseed oil phosphate ester polyols with intumescent flame retardants

“…As a blowing agent, a nitrogen‐releasing compound, melamine, is commonly used. It is used not only because it effectively suppresses the smoke production during the initial combustion stage of PU foams but also, at definite combinations with phosphorus‐containing FR, it could manifest phosphorus‐nitrogen synergism …”