Hexamethoxycyclotriphosphazene as a flame retardant for polyurethane foams

Abstract

Polyurethane (PU) foams were protected by phosphorous and nitrogen-based molecular flame retardant hexamethoxycyclotriphosphazene c-[N=P(OMe)2]3 (HMCPT). This compound was synthesized, analyzed, and investigated with respect to its thermal behavior, compatibility, and efficiency as a flame retardant (FR) for PU foams. The decomposition of HMCPT starts at 186°C in air and under argon, as indicated by TG/DSC measurements. It was possible to introduce 5 per hundred parts polyol (phpp) of HMCPT into the PU foams. The mechanical and morphological characteristics of the protected foams-compression load deflection, tenacity, tensile elongation, air perviousness, and raw density-were investigated indicating that the FR has an impact on all of these properties. The flame retardancy was evaluated with the FM VSS 302 test, where an self-extinguishing classification was reached with 5phpp of HMCPT. Cone calorimeter measurements provide evidence for a flame poisoning mechanism

Synthesis of a melamine‐cyclotriphosphazene derivative and its application as flame retardant on cotton gauze

“…When MCP is incorporated into the network of cotton gauze (for example: gauze 4), the decomposition temperature of MCP is lower than naked cotton gauze (gauze 0), then the formation of the gas and the produce of phosphate protective the gauze to slow decomposition. This phenomenon is consistent with flame retardant plastics containing cyclotriphosphazenes in a lot of literature . So the MCP can enhance the thermal properties of the gauze due to the synergistic effects of flame‐retardant phosphorous and nitrogen content.…”

“…Because the thermal decomposition of phosphazene‐based polymers is an endothermic process, and the phosphate, metaphosphate, and polyphosphate generated during the thermal decomposition form a nonvolatile protective film on the surface of the polymer which has the effect of isolating it from the air. Meanwhile, the gases released, including CO 2 , NH 3 and N 2 , are not flammable and also serve to cut off the supply of oxygen, leading to a synergistic increase in flame retardancy . Moreover, the increase of the residue was found when MCP was loaded in the cotton gauze.…”

“…Phosphazenes are a kind of hybrid organic–inorganic materials with alternating nitrogen and phosphorus atoms in the main chains. Materials containing phosphazenes tend to be thermally‐ and chemically‐stable and have been shown to provide improved flame‐retardant and heat‐resistant properties to reinforced polymers . In addition to their flame‐retardant behavior, they also exhibit unusual thermal properties such as self‐extinguishability .…”

“…Materials containing phosphazenes tend to be thermallyand chemically-stable and have been shown to provide improved flame-retardant and heat-resistant properties to reinforced polymers. [7][8][9] In addition to their flame-retardant behavior, they also exhibit unusual thermal properties such as selfextinguishability. 10,11 More importantly, phosphazene materials are halogen-free and environmentally-friendly, with some compounds even demonstrating biocompatibility.…”

Preparation, flame retardancy, and thermal and mechanical properties of polyurethane containing phosphonated bisphenol‐A units

“…Basically, flame retardants can be either reactive or additive. The addition type includes phosphates, clay, carbon nanotubes, expandable graphite, and metal compounds such as aluminum hydroxide and magnesium hydroxide . However, these additives are usually used at a high load content, and deteriorate the physical properties of PUs.…”