Experimental study of burning behaviors of intumescent coatings and nanoparticles applied on flaxboard

Abstract

This article presents an experimental investigation of ignition and burning behaviors of intumescent coatings and nanoparticles applied on flaxboard using the cone calorimeter, single burning item (SBI) and reduced scale (one-third) ISO room. The effects of intumescent coatings and nanoparticles on time to ignition (TTI), mass loss rate (MLR), heat release rate (HRR), production of toxic gases (carbon monoxide and smoke) were investigated. The performance of intumescent coatings in under-ventilated condition was examined by performing tests in the one-third ISO room with reduced opening sizes. Results in the cone calorimeter and SBI indicated that (1) there is a substantial increase of TTI and decrease of MLR/HRR by intumescent coatings and (2) the addition of nanoparticles results in a further increase of TTI as well as a decrease of MLR/HRR owing to increased stability of the char. Tests in the one-third ISO room showed that although the intumescent coatings reduce the HRR the reduction is much less substantial than that in the cone calorimeter or SBI.

Fire performance of brominated and halogen‐free flame retardants in glass‐fiber reinforced poly(butylene terephthalate)

“…The results of PG3 are similar to those of PG4, indicating that nanoclay does not affect the decomposition of the materials. As shown in Zhang et al, the primary effect of nanoclay is that it forms a protection char layer for neat polymers or enhances the char strength of FRs or intumescent coating, and such physical actions of nanoclay cannot be observed for the thermally thin materials as tested by TGA; consequently, the effect of nanoclay is minimal in microscale experiments. However, as it will be shown in the cone calorimeter results, nanoclay can have a significant effect on the fire retardancy when combined with Alpi.…”

Experimental and Numerical Study of Thermal Stability and Fire Performance of Brominated and Halogen-free Flame Retardants in Glass-fibre Reinforced Poly(butylene terephthalate)

“…However its second peak HRR is close to that of PG1. The present results are similar to those reported in [15], where a decrease of about 45% in the first peak HRR was achieved whilst no difference was noted for the second peak HRR when 20% Alpi was used in PBT+GF.…”

“…3. It was reported in [15] that the decomposition process of Alpi depends on experimental conditions (such as the size of the crucible and the mass of the sample) and that two different decomposition behaviours are observed depending on these conditions: vaporization of Alpi as a complete molecule (around 275 o C) or decomposition of Alpi (435 o C). The amount of residue changes depending on the process.…”

“…The results of PG3 are similar to those of PG4, indicating that nanoclay does not affect the decomposition of the materials. As shown in [13][14][15], the primary effect of nanoclay is that it forms a protection char layer for neat polymers or enhances the char strength of FRs or intumescent coating and such physical actions of nanoclay cannot be observed for the thermally thin materials as tested by TGA; consequently the effect of nanoclay is minimal in micro-scale experiments. However as it will be shown later in the cone calorimeter results that nanoclay can have a significant effect on the fire retardancy when combined with Alpi.…”

“…The main fire retardant mechanism of Alpi is that it intumescences upon heating, forming a thick intumescent layer that protects the unpyrolysed material from heating and thus pyrolysis [11,12]. Nanoclays, while having limited effect on degradation of polymers in thermogravimetric analysis (TGA) where mg samples are used, have also been shown to have an important effect in reduce the heat release rate/mass loss rate in the cone calorimeter, owing to the formation of a surface layer after polymer composites degrade and nanoparticles are left behind or to increased strength and integrity of the char when nanoclays are added to FRs (phosphorus-based or intumescent coatings) [13][14][15].…”