Isocyanate emissions from pyrolysis of mattresses containing polyurethane foam.
Chemosphere
; 168: 667-675, 2017 Feb.
Article
em En
| MEDLINE
| ID: mdl-27836276
ABSTRACT
This study examined the emissions of powerful asthmatic agents called isocyanates from small-scale pyrolysis experiments of two common foams employed in mattress production such as flexible polyurethane foam (FPUF) and viscoelastic memory foam (VMF). A nitrogen atmosphere and five different temperatures, 300, 350, 400, 450 and 850 °C, were selected to carry out the experiments in order to evaluate the worst possible conditions for thermal degradation. A similar trend for both materials was found. At lower temperatures, diisocyanates were the most important products whereas at 850 °C monoisocyanates, and mainly isocyanic acid released mainly from the thermal cracking of diisocyanates evolved directly from the polymer chains. The total yields of isocyanates were in the range of 1.43-11.95 mg/m3 for FPUF at 300-850 °C and 0.05-6.13 mg/m3 for VMF, 300-850 °C. This difference could be a consequence of the lower amount of isocyanates employed in the VMF production which was confirmed by the nitrogen content of the foams, 5.95% FPUF vs. 3.34% in VMF. Additionally, a qualitative search for so far unknown isocyanates was performed in samples from the pyrolysis of FPUF at 300, 400 and 850 °C. It was confirmed that six different aminoisocyanates at 300 °C were evolved, whereas at 400 and 850 °C only five of them were detected. The general trend observed was a decrease of the aminoisocyanate levels with increasing pyrolysis temperature.
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Base de dados:
MEDLINE
Assunto principal:
Poliuretanos
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Leitos
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Monitoramento Ambiental
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Isocianatos
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Poluentes Atmosféricos
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Modelos Teóricos
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article