Influence of flame retardants on thermal decomposition of wood fibre insulation quantified by integrated thermal analysis
Sudhoff, Patrick LU ; Hansen-Bruhn, Iben and Wilkens, Konrad LU
(2026)
In Fire Safety Journal
165.
- Abstract
This study investigates how flame retardants influence the thermal decomposition pathways of wood fibre insulation, with particular emphasis on distinguishing condensed-phase reactions from gas-phase combustibility and their implications for fire behaviour. Two loose-fill wood fibre insulation materials were studied, with an ammonium salt-treated sample compared to an untreated reference. An integrated approach combining thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and microscale combustion calorimetry (MCC) was applied under inert and oxidative conditions at multiple heating rates. In addition, model-free kinetic analysis using the Friedman method was... (More)
This study investigates how flame retardants influence the thermal decomposition pathways of wood fibre insulation, with particular emphasis on distinguishing condensed-phase reactions from gas-phase combustibility and their implications for fire behaviour. Two loose-fill wood fibre insulation materials were studied, with an ammonium salt-treated sample compared to an untreated reference. An integrated approach combining thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and microscale combustion calorimetry (MCC) was applied under inert and oxidative conditions at multiple heating rates. In addition, model-free kinetic analysis using the Friedman method was performed to determine activation energy as a function of conversion based on both TGA and MCC data. The flame-retardant-treated material (WL-h-10) exhibits a distinct decomposition pathway compared to the untreated reference (WL-h-Ref). TGA and MCC show an earlier onset of decomposition, shifted to lower temperatures by ∼100 K, together with a clear reduction in peak mass-loss rate by ∼43%, peak heat release rate by ∼75%, and effective heat of combustion of the evolved volatiles by ∼46%. In contrast, DSC indicates only minor changes in the total heat of reaction, distributed over a broader temperature range of 120–150 K. FTIR analysis reveals a shift toward dehydration and carbonisation, leading to reduced emission of combustible volatiles and increased char formation (+65%). These results indicate a predominantly condensed-phase flameretardant mechanism that reduces flammability by limiting the release of combustible volatiles. However, increased char yield and extended oxidation may favour smouldering, highlighting the need to distinguish between flaming and smouldering behaviour.
(Less)
- author
- Sudhoff, Patrick
LU
; Hansen-Bruhn, Iben
and Wilkens, Konrad
LU
- organization
- publishing date
- 2026-11
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Flame retardant, Flammability, Reaction kinetics, Smouldering, Thermal analysis, Wood fiber insulation
- in
- Fire Safety Journal
- volume
- 165
- article number
- 104945
- publisher
- Elsevier
- external identifiers
-
- scopus:105046607971
- ISSN
- 0379-7112
- DOI
- 10.1016/j.firesaf.2026.104945
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2026 The Authors.
- id
- 860fb054-469f-4906-88d4-7ab6292b20fc
- date added to LUP
- 2026-09-25 09:28:08
- date last changed
- 2026-09-25 09:29:17
@article{860fb054-469f-4906-88d4-7ab6292b20fc,
abstract = {{<p>This study investigates how flame retardants influence the thermal decomposition pathways of wood fibre insulation, with particular emphasis on distinguishing condensed-phase reactions from gas-phase combustibility and their implications for fire behaviour. Two loose-fill wood fibre insulation materials were studied, with an ammonium salt-treated sample compared to an untreated reference. An integrated approach combining thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and microscale combustion calorimetry (MCC) was applied under inert and oxidative conditions at multiple heating rates. In addition, model-free kinetic analysis using the Friedman method was performed to determine activation energy as a function of conversion based on both TGA and MCC data. The flame-retardant-treated material (WL-h-10) exhibits a distinct decomposition pathway compared to the untreated reference (WL-h-Ref). TGA and MCC show an earlier onset of decomposition, shifted to lower temperatures by ∼100 K, together with a clear reduction in peak mass-loss rate by ∼43%, peak heat release rate by ∼75%, and effective heat of combustion of the evolved volatiles by ∼46%. In contrast, DSC indicates only minor changes in the total heat of reaction, distributed over a broader temperature range of 120–150 K. FTIR analysis reveals a shift toward dehydration and carbonisation, leading to reduced emission of combustible volatiles and increased char formation (+65%). These results indicate a predominantly condensed-phase flameretardant mechanism that reduces flammability by limiting the release of combustible volatiles. However, increased char yield and extended oxidation may favour smouldering, highlighting the need to distinguish between flaming and smouldering behaviour.</p>}},
author = {{Sudhoff, Patrick and Hansen-Bruhn, Iben and Wilkens, Konrad}},
issn = {{0379-7112}},
keywords = {{Flame retardant; Flammability; Reaction kinetics; Smouldering; Thermal analysis; Wood fiber insulation}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Fire Safety Journal}},
title = {{Influence of flame retardants on thermal decomposition of wood fibre insulation quantified by integrated thermal analysis}},
url = {{http://dx.doi.org/10.1016/j.firesaf.2026.104945}},
doi = {{10.1016/j.firesaf.2026.104945}},
volume = {{165}},
year = {{2026}},
}