Shedding new light on polyurethane degradation

Assessing foams condition in design objects

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

A new insight into the degradation of polyurethane (PUR) slabstock foams is suggested by studying historical design objects and PUR references submitted to natural ageing. PUR foams are segregated structures comprising hard and soft domains, as well as chemical and physical crosslinking (H-bonds). H-bonds have been commonly followed in polymerisation studies of PUR foams by monitoring carbonyl bands in the infrared. Their fundamental role in PUR physical properties has been stressed; however, their liability to natural ageing has been poorly focused, with few studies suggesting their vulnerability to high temperature and humidity. As PUR has a short lifespan, and many objects show severe degradation signs (yellowing, crumbling and brittleness), the in-depth analysis of PUR foams behaviour upon natural ageing, as well as the monitoring of H-bonds over these processes is discussed in this paper. References of PUR slabstock foams (ether-based polyols and toluene diisocyanates) were produced; and infrared micro-spectroscopy and optical microscopy (under darkfield, polarised light and UV light) were selected to assess PUR ageing. A visual (micro level) and molecular pathway for PUR natural ageing is suggested, and deterioration signs (yellowing, micro holes, pitting and cracks) on PUR cell buns were translated into specific infrared fingerprints (assigned to N–H, C–H and C=O stretching absorptions). As the C=O band at c. 1640 cm−1 (indicator of PUR hard domain ordered structure) showed considerable changes upon PUR ageing, this study confirms H-bonds as liable to natural ageing, and proposes this band as marker of ether-based PUR slabstock foam condition.

Original languageEnglish
Pages (from-to)354-365
Number of pages12
JournalPolymer Degradation and Stability
Volume144
DOIs
Publication statusPublished - Oct 2017

Fingerprint

Polyurethanes
polyurethane foam
foams
Foams
degradation
Aging of materials
Degradation
Infrared radiation
ethers
Ether
liabilities
Toluene 2,4-Diisocyanate
diisocyanates
brittleness
vulnerability
pitting
crosslinking
Monitoring
deterioration
markers

Keywords

  • Condition assessment
  • Hydrogen-bonding
  • Infrared spectroscopy
  • Natural ageing
  • Optical microscopy
  • Polyurethane foam

Cite this

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title = "Shedding new light on polyurethane degradation: Assessing foams condition in design objects",
abstract = "A new insight into the degradation of polyurethane (PUR) slabstock foams is suggested by studying historical design objects and PUR references submitted to natural ageing. PUR foams are segregated structures comprising hard and soft domains, as well as chemical and physical crosslinking (H-bonds). H-bonds have been commonly followed in polymerisation studies of PUR foams by monitoring carbonyl bands in the infrared. Their fundamental role in PUR physical properties has been stressed; however, their liability to natural ageing has been poorly focused, with few studies suggesting their vulnerability to high temperature and humidity. As PUR has a short lifespan, and many objects show severe degradation signs (yellowing, crumbling and brittleness), the in-depth analysis of PUR foams behaviour upon natural ageing, as well as the monitoring of H-bonds over these processes is discussed in this paper. References of PUR slabstock foams (ether-based polyols and toluene diisocyanates) were produced; and infrared micro-spectroscopy and optical microscopy (under darkfield, polarised light and UV light) were selected to assess PUR ageing. A visual (micro level) and molecular pathway for PUR natural ageing is suggested, and deterioration signs (yellowing, micro holes, pitting and cracks) on PUR cell buns were translated into specific infrared fingerprints (assigned to N–H, C–H and C=O stretching absorptions). As the C=O band at c. 1640 cm−1 (indicator of PUR hard domain ordered structure) showed considerable changes upon PUR ageing, this study confirms H-bonds as liable to natural ageing, and proposes this band as marker of ether-based PUR slabstock foam condition.",
keywords = "Condition assessment, Hydrogen-bonding, Infrared spectroscopy, Natural ageing, Optical microscopy, Polyurethane foam",
author = "{Fran{\cc}a de S{\'a}}, Susana and Ferreira, {Joana Lia} and {Pombo Cardoso}, Isabel and Rita Macedo and Ramos, {Ana Maria}",
note = "The authors are thankful to Flexipol Espumas Sinteticas S.A. for the PUR reference sample, to Professor Joao Carlos Moura Bordado for the enlightening discussion on the behaviour of PUR flexible foams, and to Dr. Marisa Pamplona and Dr. Elke Cwiertnia from the Deutsches Museum for the Py-GC/MS analysis of the reference sample. This work was supported by the Associate Laboratory for Green Chemistry LAQV which is financed by national funds from FCT/MEC (UID/QUI/50006/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER - 007265), as well as by the doctoral grant 5FM-0D/78862/ 201, financially supported by FCIIMEC.",
year = "2017",
month = "10",
doi = "10.1016/j.polymdegradstab.2017.08.028",
language = "English",
volume = "144",
pages = "354--365",
journal = "Polymer Degradation and Stability",
issn = "0141-3910",
publisher = "Elsevier Science B.V., Amsterdam.",

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TY - JOUR

T1 - Shedding new light on polyurethane degradation

T2 - Assessing foams condition in design objects

AU - França de Sá, Susana

AU - Ferreira, Joana Lia

AU - Pombo Cardoso, Isabel

AU - Macedo, Rita

AU - Ramos, Ana Maria

N1 - The authors are thankful to Flexipol Espumas Sinteticas S.A. for the PUR reference sample, to Professor Joao Carlos Moura Bordado for the enlightening discussion on the behaviour of PUR flexible foams, and to Dr. Marisa Pamplona and Dr. Elke Cwiertnia from the Deutsches Museum for the Py-GC/MS analysis of the reference sample. This work was supported by the Associate Laboratory for Green Chemistry LAQV which is financed by national funds from FCT/MEC (UID/QUI/50006/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER - 007265), as well as by the doctoral grant 5FM-0D/78862/ 201, financially supported by FCIIMEC.

PY - 2017/10

Y1 - 2017/10

N2 - A new insight into the degradation of polyurethane (PUR) slabstock foams is suggested by studying historical design objects and PUR references submitted to natural ageing. PUR foams are segregated structures comprising hard and soft domains, as well as chemical and physical crosslinking (H-bonds). H-bonds have been commonly followed in polymerisation studies of PUR foams by monitoring carbonyl bands in the infrared. Their fundamental role in PUR physical properties has been stressed; however, their liability to natural ageing has been poorly focused, with few studies suggesting their vulnerability to high temperature and humidity. As PUR has a short lifespan, and many objects show severe degradation signs (yellowing, crumbling and brittleness), the in-depth analysis of PUR foams behaviour upon natural ageing, as well as the monitoring of H-bonds over these processes is discussed in this paper. References of PUR slabstock foams (ether-based polyols and toluene diisocyanates) were produced; and infrared micro-spectroscopy and optical microscopy (under darkfield, polarised light and UV light) were selected to assess PUR ageing. A visual (micro level) and molecular pathway for PUR natural ageing is suggested, and deterioration signs (yellowing, micro holes, pitting and cracks) on PUR cell buns were translated into specific infrared fingerprints (assigned to N–H, C–H and C=O stretching absorptions). As the C=O band at c. 1640 cm−1 (indicator of PUR hard domain ordered structure) showed considerable changes upon PUR ageing, this study confirms H-bonds as liable to natural ageing, and proposes this band as marker of ether-based PUR slabstock foam condition.

AB - A new insight into the degradation of polyurethane (PUR) slabstock foams is suggested by studying historical design objects and PUR references submitted to natural ageing. PUR foams are segregated structures comprising hard and soft domains, as well as chemical and physical crosslinking (H-bonds). H-bonds have been commonly followed in polymerisation studies of PUR foams by monitoring carbonyl bands in the infrared. Their fundamental role in PUR physical properties has been stressed; however, their liability to natural ageing has been poorly focused, with few studies suggesting their vulnerability to high temperature and humidity. As PUR has a short lifespan, and many objects show severe degradation signs (yellowing, crumbling and brittleness), the in-depth analysis of PUR foams behaviour upon natural ageing, as well as the monitoring of H-bonds over these processes is discussed in this paper. References of PUR slabstock foams (ether-based polyols and toluene diisocyanates) were produced; and infrared micro-spectroscopy and optical microscopy (under darkfield, polarised light and UV light) were selected to assess PUR ageing. A visual (micro level) and molecular pathway for PUR natural ageing is suggested, and deterioration signs (yellowing, micro holes, pitting and cracks) on PUR cell buns were translated into specific infrared fingerprints (assigned to N–H, C–H and C=O stretching absorptions). As the C=O band at c. 1640 cm−1 (indicator of PUR hard domain ordered structure) showed considerable changes upon PUR ageing, this study confirms H-bonds as liable to natural ageing, and proposes this band as marker of ether-based PUR slabstock foam condition.

KW - Condition assessment

KW - Hydrogen-bonding

KW - Infrared spectroscopy

KW - Natural ageing

KW - Optical microscopy

KW - Polyurethane foam

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DO - 10.1016/j.polymdegradstab.2017.08.028

M3 - Article

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EP - 365

JO - Polymer Degradation and Stability

JF - Polymer Degradation and Stability

SN - 0141-3910

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