Flammability of thermoplastic carbon nanofiber nanocomposites

Abstract

SUMMARYFive commodity thermoplastics (polyethylene, polypropylene, thermoplastic polyurethane, poly(butylene terephthalate), and poly(amide 6)) were melt compounded with vapor grown carbon nanofibers via twin screw extrusion. These materials were then analyzed for flammability behavior by cone calorimeter to determine how the nanofibers would reduce flammability of the polymers. It was found by cone calorimeter that the nanofibers greatly reduced peak heat release rate and improved many other flammability parameters of the samples. However, smoke release was increased in all samples, which may be one drawback of using these materials. Interestingly, the amount of flammability reduction was not uniform across all samples, with nanofiber reducing flammability the most in the thermoplastic polyurethane sample. The mechanism of flammability reduction in the polymers tested in this paper is shown again to be a mass loss rate reduction induced by the formation of thick tangled networks of carbon nanofibers during polymer decomposition. This mechanism was confirmed by studying the mass loss rate curves and electron microscopy analysis of the final chars collected from the cone calorimeter experiments.

Characterization of melt‐compounded and masterbatch‐diluted polypropylene composites filled with several fillers

“…One flammability property, which deteriorated and, in fact, increased with the addition of fillers, was smoke release during combustion. This agrees with Morgan and Liu's [16] results on PP/carbon nanofiber composites. They concluded that large mass loss fragments may pyrolyze because of a delayed mass loss rate.…”

“…Furthermore, Laachachi et al [15] successfully used nano‐sized titanium oxide to increase the fire resistance of poly(methyl methacrylate). The often increased flame retardancy properties obtained with nanofillers (and other halogen‐free fire retardants) are rather polymer specific, which means that while one nanofiller works well in one polymer, it may not work at all in another [16]. To our knowledge, no systematic study has so far been carried out comparing the effect of selected plate, spherical, and tubular nanoparticles on the flammability of PP.…”

Intumescing multilayer thin film deposited on clay-based nanobrick wall to produce self-extinguishing flame retardant polyurethane

“…The maximum average rate of heat emission (MARHE) is reduced in all coated samples, with the greatest reduction observed in the combination coating (56 %). The MARHE is a useful parameter for ranking materials in terms of ability to support flame spread to other objects [45], meaning the clay-intumescent stack is the least likely to spread a fire to another object. This unique combination of two flame retardant mechanisms in a single nanocoating serves to render a commonly used material in home furnishings largely inflammable.…”

Aluminum hydroxide multilayer assembly capable of extinguishing flame on polyurethane foam

“…The peak HRR of 6 BL PEMcoated foam (736 kW m -2 ) represented a reduction of only 16 %. The total heat release was actually increased to 23.5 MJ m -2 due to the coating adding more flammable [52], indicating a reduced fire hazard imparted by the PEM-ATH coating.…”