am0c00567_si_001.pdf (175.21 kB)
Intumescent, Epoxy-Based Flame-Retardant Coatings Based on Poly(acrylic acid) Compositions
journal contribution
posted on 2020-04-10, 11:36 authored by Erik J. Price, James Covello, Andrew Tuchler, Gary E. WnekIntumescent coatings
expand upon exposure to a flame to create
a protective char layer between the flame and underlying substrate.
Widely used commercially, these coatings are applied notably to steel
load-bearing beams, significantly extending their time to failure.
Boric acid has proved to be a particularly effective additive in the
formulation in these coatings, although regulatory concerns are driving
an urgent need for more environmentally friendly additives. We report
here the characterization of poly(acrylic acid) (PAA) for its use
as a novel material in flame-retardant and intumescent coatings. Thermogravimetric
analysis (TGA) and microscale combustion calorimetry (MCC) were performed
on the novel flame-retardant additives to evaluate individual degradation
mechanisms and heat release rates. Promising compositions were immobilized
in an epoxy binder and formulated with other intumescent additives
such as ammonium polyphosphate (APP) and melamine (MEL) to evaluate
performance in a coating system. These formulations were then evaluated
via quantitative cone calorimetry. Particular PAA-containing formulations
show peak heat release rates (PHRR) and total heat release (THR) of
283 kW/m2 and 50.5 MJ/m2, respectively, which
compare favorably to data for BA-containing systems, specifically
PHRR = 229 kW/m2 and THR = 43.1 MJ/m2. Results
showed promise and need for further investigation into PAA as a multifunctional
additive for use in flame-retardant and intumescent coatings.