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Viscoelastic Polyurethane Foams for Use in Seals of Respiratory Protective Devices

A key factor in effective protection against airborne hazards, i.e., biological and nonbiological aerosols, vapors, and gases, is a good face fit of respiratory protective devices (RPDs). Equally important is the comfort of use, which may encourage or discourage users from donning RPDs. The objectiv...

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Autores principales: Okrasa, Małgorzata, Leszczyńska, Milena, Sałasińska, Kamila, Szczepkowski, Leonard, Kozikowski, Paweł, Majchrzycka, Katarzyna, Ryszkowska, Joanna
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8036923/
https://www.ncbi.nlm.nih.gov/pubmed/33805934
http://dx.doi.org/10.3390/ma14071600
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author Okrasa, Małgorzata
Leszczyńska, Milena
Sałasińska, Kamila
Szczepkowski, Leonard
Kozikowski, Paweł
Majchrzycka, Katarzyna
Ryszkowska, Joanna
author_facet Okrasa, Małgorzata
Leszczyńska, Milena
Sałasińska, Kamila
Szczepkowski, Leonard
Kozikowski, Paweł
Majchrzycka, Katarzyna
Ryszkowska, Joanna
author_sort Okrasa, Małgorzata
collection PubMed
description A key factor in effective protection against airborne hazards, i.e., biological and nonbiological aerosols, vapors, and gases, is a good face fit of respiratory protective devices (RPDs). Equally important is the comfort of use, which may encourage or discourage users from donning RPDs. The objective of the work was to develop viscoelastic polyurethane foams for use in RPD seals. The obtained foams were characterized using scanning electron microscopy, infrared spectroscopy, thermogravimetry, and differential scanning calorimetry. Measurements also involved gel fraction, apparent density, air permeability, elastic recovery time, compression set, rebound resilience, and sweat uptake. The results were discussed in the context of modifications to the foam formulation: the isocyanate index (I(NCO)) in the range of 0.6–0.9 and the blowing agent content in the range of 1.2–3.0 php. FTIR analysis revealed a higher level of urea groups with increasing water content in the formulation. Higher I(NCO) and water content levels also led to lower onset temperatures of thermal degradation and higher glass-transition temperatures of the soft phase. A decrease in apparent density and an increase in mean pore sizes of the foams with increasing I(NCO) and water content levels was observed. Functional parameters (air permeability, elastic recovery time, compression set, rebound resilience, and sweat uptake) were also found to be satisfactory at lower I(NCO) and water content levels.
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spelling pubmed-80369232021-04-12 Viscoelastic Polyurethane Foams for Use in Seals of Respiratory Protective Devices Okrasa, Małgorzata Leszczyńska, Milena Sałasińska, Kamila Szczepkowski, Leonard Kozikowski, Paweł Majchrzycka, Katarzyna Ryszkowska, Joanna Materials (Basel) Article A key factor in effective protection against airborne hazards, i.e., biological and nonbiological aerosols, vapors, and gases, is a good face fit of respiratory protective devices (RPDs). Equally important is the comfort of use, which may encourage or discourage users from donning RPDs. The objective of the work was to develop viscoelastic polyurethane foams for use in RPD seals. The obtained foams were characterized using scanning electron microscopy, infrared spectroscopy, thermogravimetry, and differential scanning calorimetry. Measurements also involved gel fraction, apparent density, air permeability, elastic recovery time, compression set, rebound resilience, and sweat uptake. The results were discussed in the context of modifications to the foam formulation: the isocyanate index (I(NCO)) in the range of 0.6–0.9 and the blowing agent content in the range of 1.2–3.0 php. FTIR analysis revealed a higher level of urea groups with increasing water content in the formulation. Higher I(NCO) and water content levels also led to lower onset temperatures of thermal degradation and higher glass-transition temperatures of the soft phase. A decrease in apparent density and an increase in mean pore sizes of the foams with increasing I(NCO) and water content levels was observed. Functional parameters (air permeability, elastic recovery time, compression set, rebound resilience, and sweat uptake) were also found to be satisfactory at lower I(NCO) and water content levels. MDPI 2021-03-25 /pmc/articles/PMC8036923/ /pubmed/33805934 http://dx.doi.org/10.3390/ma14071600 Text en © 2021 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 (http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) ).
spellingShingle Article
Okrasa, Małgorzata
Leszczyńska, Milena
Sałasińska, Kamila
Szczepkowski, Leonard
Kozikowski, Paweł
Majchrzycka, Katarzyna
Ryszkowska, Joanna
Viscoelastic Polyurethane Foams for Use in Seals of Respiratory Protective Devices
title Viscoelastic Polyurethane Foams for Use in Seals of Respiratory Protective Devices
title_full Viscoelastic Polyurethane Foams for Use in Seals of Respiratory Protective Devices
title_fullStr Viscoelastic Polyurethane Foams for Use in Seals of Respiratory Protective Devices
title_full_unstemmed Viscoelastic Polyurethane Foams for Use in Seals of Respiratory Protective Devices
title_short Viscoelastic Polyurethane Foams for Use in Seals of Respiratory Protective Devices
title_sort viscoelastic polyurethane foams for use in seals of respiratory protective devices
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8036923/
https://www.ncbi.nlm.nih.gov/pubmed/33805934
http://dx.doi.org/10.3390/ma14071600
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