The flammability of expandable polystyrene foams coated with melamine modified urea formaldehyde resin

Abstract

Urea formaldehyde resin (UF) was modified by introducing melamine during the condensation in order to reduce the amount of free formaldehyde and increase the solid content. The melamine modified UF (MUF) was firstly mixed with intumescent flame retardant (IFR) and then coated on the surface of pre‐expanded polystyrene (PS) particles to prepare flame retardant expandable PS (EPS) foams. The flammability of EPS foam samples was characterized by limiting oxygen index (LOI), UL‐94 vertical burning and cone calorimeter tests, and the results indicated that the peak heat release rate was significantly reduced from 406 to 49 kW/m2 and LOI value could reach 36.3 with V‐0 rating in UL‐94 test after coated with IFR. The smoke density test indicated that the maximum smoke density was decreased by the addition of IFR. Thermal analysis suggested that the thermal stability and char formation were significantly improved by the presence of coated flame retardants. The residual char observation revealed that MUF and IFR were beneficial to form integrated char layers with hollow stents, which could be the main reason for the improvement of flame retardant properties. The mechanical properties of flame retardant EPS foams can still meet the standard requirements for industrial applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44423.

Lignosulfonates as Fire Retardants in Wood Flour-Based Particleboards

“…The enhancement was detected on modulus and strength as well, and it can be attributed to the reinforcing action of APP towards UF resin due to the good physical interactions between the two components [40]. The good compatibility between APP and UF resin has also been used in other FR formulations [41].…”

Study on the effect of PolyFR and its FR system on the flame retardancy and foaming behavior of polystyrene

“…[1][2][3][4][5][6] But PS foam is an extremely ammable material; the LOI value of PS foam is only about 18% and has no UL-94 rating. 7 Therefore, research on ame-retardant PS foam is necessary. Hexabromocyclododecane (HBCD), a traditional ame retardant of polystyrene foam, which can endow PS with excellent ame-retardant performance at a typical loading between 0.8 and 4.0 wt% (ref.…”

“…8,12 Some systems had been applied to ame retardant PS and PS foam, such as nitrogen phosphorus ame retardants and intumescent ame retardants. 7,[13][14][15][16][17][18] Besides organic ame-retardant additives, inorganic ame-retardant additives including layered double hydroxide of zinc aluminum and zinc magnesium 19 carbon nanotubes 20 and nanoclays, [21][22][23] can also effectively reinforce ame-retardant properties of PS and PS foam. But in order to attain outstanding ame-retardant properties, the content of ame retardants is usually more than 20 wt%.…”

Flame‐retardant expandable polystyrene foams coated with ethanediol‐modified melamine–formaldehyde resin and microencapsulated ammonium polyphosphate

“…Expandable polystyrene (EPS) is a kind of foamed material that is lightweight and possesses excellent shock absorption, moisture resistance, and thermal insulation properties. Therefore, it has been widely used as packaging, cushioning, and insulation materials . However, the limiting oxygen index of neat EPS foam is only 17%, which makes it highly flammable .…”

“…Intumescent flame retardants (IFR) are halogen‐free flame retardants that have been proposed as one of the most promising environmentally friendly candidates owing to their excellent properties, including low toxicity and dripping resistance . In our previous work, an intumescent flame‐retardant system was successfully used to enhance the fire resistance of EPS foams . Ammonium polyphosphate (APP) is one of the most important forms of IFRs and acts as an acid source .…”