Improving the fire performance and smoke suppression of expandable polystyrene foams by coating with multi‐dimensional carbon nanoparticles

Abstract

Expandable graphite (EG) and modified multi‐wall carbon nanotubes (ATH‐MWNT) were introduced to expandable polystyrene (EPS) foams in order to improve its fire performance. The fire performance of EPS foams was evaluated by limiting the oxygen index (LOI), vertical burning (UL‐94), and cone calorimetry tests. The results showed that the presence of 14.3% EG and 4.1% ATH‐MWNT increased the LOI value from 18.0 to 30.3%, upgraded the UL‐94 rating from no rating to V‐0, completely eliminated melt dripping, and significantly decreased the peak heat release rate from 933 to 177 kW/m2. Thermal analysis indicated that the thermal stability and char formation were improved by the presence of flame retardants. The char morphology was characterized by scanning electronic microscopy (SEM). It was suggested that the presence of EG and ATH‐MWNT could form integrated char layers during combustion, which was beneficial to the formation of an intumescent protective char structure.

Synergistic Function between Phosphorus-Containing Flame Retardant and Multi-Walled Carbon Nanotubes towards Fire Safe Polystyrene Composites with Enhanced Electromagnetic Interference Shielding

“…In order to further analyze the chemical structure of the char residuals of PS composites, the char residuals of PS composites were tested by FTIR, as presented in Figure 7 h. The characteristic absorption peak situated at 3439 cm −1 belongs to the stretching vibration of -OH of carboxyl in aMWCNT [ 44 ]. The absorption peaks at 1624 cm −1 and 1390 cm −1 correspond to the stretching vibration of C=C and the stretching vibration of C=O, respectively [ 45 ]. The peak attributed to the stretching vibration of Si-O-Si occurs at 1153 cm −1 [ 23 ].…”

“…Moreover, the introduction of aMWCNT further enhances the flame-retardant properties. The synergistic effect between SiAPP and aMWCNT can catalyze the generation of robust char layers [ 45 ], which can block the heat transfer and combustible gas migration, and retard the thermal decomposition of PS composites. When the PS composites are burned, SiAPP and aMWCNT will produce magnanimous inert gases (NH 3 , H 2 O, and CO 2 , etc.…”

Preparation of Hydrophilic and Fire-Resistant Phytic Acid/Chitosan/Polydopamine-Coated Expanded Polystyrene Particles by Using Coating Method

“…The coating method, by coating each EPS particle surface with an adhesive and flame-retardant, is a good flameretardant modification method [22,23]. Cao et al [24] used aluminum nitrate-modified multi-walled carbon nanotubes (ATH-MWNTs) and expandable graphite (EG) for EPS flame-retardant modification using melamine-modified urea formaldehyde resin (MUF) as an adhesive with the encapsulation method. The modified EPS foams achieved a limiting oxygen index (LOI) of 30.3% and a UL-94 rating of V-0 when 14.3 wt% EG and 4.1 wt% ATH-MWNTs were added, and the peak of the heat release rate (pHRR) was reduced from 933 to 177 kW/m 2 .…”

Induced assembly of polystyrene composites for simultaneously improving flame retardant and electromagnetic shielding properties

“…Polystyrene (PS) has a wide range of applications in the fields of the electronic and electrical equipment, automotive, construction and aerospace because of its unexceptionable performances, including good dimensional stability, heat resistance, low density, mechanical durability and easy processing 1 . In the last few years, the annual consumption of PS materials reached more than two million tons 2 . However, PS material has a highly flammable characteristic and generates a large amount of toxic flue gas, and serious melting drops occur during the combustion, causing great economic losses and casualties 3,4 .…”