Cargando…
Expandable Graphite as a Multifunctional Flame-Retarding Additive for Highly Filled Thermal Conductive Polymer Formulations
Expandable graphite (EG) and graphite (G) were assessed as multifunctional additives improving both flame retardancy and thermal conductivity in highly filled, thermal conductive polymeric materials based on polyamide 6 (PA6). Fire testing was conducted using modern UL-94, LOI and cone calorimeter t...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9031968/ https://www.ncbi.nlm.nih.gov/pubmed/35458364 http://dx.doi.org/10.3390/polym14081613 |
_version_ | 1784692523950669824 |
---|---|
author | Tomiak, Florian Schneider, Kevin Schoeffel, Angelina Rathberger, Klaus Drummer, Dietmar |
author_facet | Tomiak, Florian Schneider, Kevin Schoeffel, Angelina Rathberger, Klaus Drummer, Dietmar |
author_sort | Tomiak, Florian |
collection | PubMed |
description | Expandable graphite (EG) and graphite (G) were assessed as multifunctional additives improving both flame retardancy and thermal conductivity in highly filled, thermal conductive polymeric materials based on polyamide 6 (PA6). Fire testing was conducted using modern UL-94, LOI and cone calorimeter test setups. It is demonstrated that thermal conductivity can significantly influence the time to ignition, although offering little fire resistance once ignited even in highly filled systems. Thus, for PA6 formulations containing solely 70 wt.% G, the peak heat release rate (pHRR) measured in cone calorimeter tests was 193 kW/m², whereas PA6 formulations containing 20 wt.% EG/50 wt.% G did not exhibit a measurable heat development. Particular attention was paid to effect separation between thermal conductivity and residue formation. Good thermal conductivity properties are proven to be particularly effective in test scenarios where the heat impact is comparatively low and the testing environment provides good heat dissipation and convective cooling possibilities. For candle-like ignition scenarios (e.g., LOI), filling levels of >50 wt.% (G or EG/G) are shown to be sufficient to suppress ignition exclusively by thermal conductivity. V0 classifications in UL-94 vertical burning tests were achieved for PA6 formulations containing ≥70 wt.% G, ≥25 wt.% EG and ≥20 wt.% EG/25 wt.% G. |
format | Online Article Text |
id | pubmed-9031968 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-90319682022-04-23 Expandable Graphite as a Multifunctional Flame-Retarding Additive for Highly Filled Thermal Conductive Polymer Formulations Tomiak, Florian Schneider, Kevin Schoeffel, Angelina Rathberger, Klaus Drummer, Dietmar Polymers (Basel) Article Expandable graphite (EG) and graphite (G) were assessed as multifunctional additives improving both flame retardancy and thermal conductivity in highly filled, thermal conductive polymeric materials based on polyamide 6 (PA6). Fire testing was conducted using modern UL-94, LOI and cone calorimeter test setups. It is demonstrated that thermal conductivity can significantly influence the time to ignition, although offering little fire resistance once ignited even in highly filled systems. Thus, for PA6 formulations containing solely 70 wt.% G, the peak heat release rate (pHRR) measured in cone calorimeter tests was 193 kW/m², whereas PA6 formulations containing 20 wt.% EG/50 wt.% G did not exhibit a measurable heat development. Particular attention was paid to effect separation between thermal conductivity and residue formation. Good thermal conductivity properties are proven to be particularly effective in test scenarios where the heat impact is comparatively low and the testing environment provides good heat dissipation and convective cooling possibilities. For candle-like ignition scenarios (e.g., LOI), filling levels of >50 wt.% (G or EG/G) are shown to be sufficient to suppress ignition exclusively by thermal conductivity. V0 classifications in UL-94 vertical burning tests were achieved for PA6 formulations containing ≥70 wt.% G, ≥25 wt.% EG and ≥20 wt.% EG/25 wt.% G. MDPI 2022-04-15 /pmc/articles/PMC9031968/ /pubmed/35458364 http://dx.doi.org/10.3390/polym14081613 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Tomiak, Florian Schneider, Kevin Schoeffel, Angelina Rathberger, Klaus Drummer, Dietmar Expandable Graphite as a Multifunctional Flame-Retarding Additive for Highly Filled Thermal Conductive Polymer Formulations |
title | Expandable Graphite as a Multifunctional Flame-Retarding Additive for Highly Filled Thermal Conductive Polymer Formulations |
title_full | Expandable Graphite as a Multifunctional Flame-Retarding Additive for Highly Filled Thermal Conductive Polymer Formulations |
title_fullStr | Expandable Graphite as a Multifunctional Flame-Retarding Additive for Highly Filled Thermal Conductive Polymer Formulations |
title_full_unstemmed | Expandable Graphite as a Multifunctional Flame-Retarding Additive for Highly Filled Thermal Conductive Polymer Formulations |
title_short | Expandable Graphite as a Multifunctional Flame-Retarding Additive for Highly Filled Thermal Conductive Polymer Formulations |
title_sort | expandable graphite as a multifunctional flame-retarding additive for highly filled thermal conductive polymer formulations |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9031968/ https://www.ncbi.nlm.nih.gov/pubmed/35458364 http://dx.doi.org/10.3390/polym14081613 |
work_keys_str_mv | AT tomiakflorian expandablegraphiteasamultifunctionalflameretardingadditiveforhighlyfilledthermalconductivepolymerformulations AT schneiderkevin expandablegraphiteasamultifunctionalflameretardingadditiveforhighlyfilledthermalconductivepolymerformulations AT schoeffelangelina expandablegraphiteasamultifunctionalflameretardingadditiveforhighlyfilledthermalconductivepolymerformulations AT rathbergerklaus expandablegraphiteasamultifunctionalflameretardingadditiveforhighlyfilledthermalconductivepolymerformulations AT drummerdietmar expandablegraphiteasamultifunctionalflameretardingadditiveforhighlyfilledthermalconductivepolymerformulations |