TY - JOUR
T1 - Temperature-dependent pyrolysis behavior of polyurethane elastomers with different hard- and soft-segment compositions
AU - Nishiyama, Yuya
AU - Kumagai, Shogo
AU - Motokucho, Suguru
AU - Kameda, Tomohito
AU - Saito, Yuko
AU - Watanabe, Atsushi
AU - Nakatani, Hisayuki
AU - Yoshioka, Toshiaki
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant Numbers 17K20057 and 19H04306 .
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/1
Y1 - 2020/1
N2 - The pyrolysis behaviors of seven kinds of polyurethane elastomers (PUEs) with different ratios between the hard segment (HS) and soft segment (SS) were investigated for both fast pyrolysis (300, 350, 450, 850 °C) and slow pyrolysis at the heating rate of 10 °C min–1 by thermogravimetric analysis (TG), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and evolved gas analysis-mass spectrometry (EGA-MS). These PUEs were synthesized from 4,4′-diphenylmethane diisocyanate (MDI), 1,4-butane diol (BD), and poly(oxytetramethylene glycol) (PTMG). Atomic force microscopy measurements found that the HS domains were formed in PUEs containing HS, and these domains were aggregated at extremely high HS ratio. The main pyrolysate derived from HS was MDI under all conditions. In fast pyrolysis tests, the decomposition of SS proceeded sufficiently at 450 °C, and a lot of low molecular weight compounds were produced at 850 °C. In slow pyrolysis tests, three-step degradation was observed, and this degradation behavior was influenced by the HS domain and SS matrix structures. The first step is the HS pyrolysis inside the HS domain, then the HS surrounded by SS is pyrolyzed. Finally, the SS matrix is pyrolyzed. The HS pyrolysates changed from isocyanate to amine with increasing temperature. We believe that the newly found pyrolysis behavior of PUEs with different ratios between the HS and SS will promote future studies on the characterization of PUE materials and the pyrolytic recovery of chemical feedstock from PUE wastes.
AB - The pyrolysis behaviors of seven kinds of polyurethane elastomers (PUEs) with different ratios between the hard segment (HS) and soft segment (SS) were investigated for both fast pyrolysis (300, 350, 450, 850 °C) and slow pyrolysis at the heating rate of 10 °C min–1 by thermogravimetric analysis (TG), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and evolved gas analysis-mass spectrometry (EGA-MS). These PUEs were synthesized from 4,4′-diphenylmethane diisocyanate (MDI), 1,4-butane diol (BD), and poly(oxytetramethylene glycol) (PTMG). Atomic force microscopy measurements found that the HS domains were formed in PUEs containing HS, and these domains were aggregated at extremely high HS ratio. The main pyrolysate derived from HS was MDI under all conditions. In fast pyrolysis tests, the decomposition of SS proceeded sufficiently at 450 °C, and a lot of low molecular weight compounds were produced at 850 °C. In slow pyrolysis tests, three-step degradation was observed, and this degradation behavior was influenced by the HS domain and SS matrix structures. The first step is the HS pyrolysis inside the HS domain, then the HS surrounded by SS is pyrolyzed. Finally, the SS matrix is pyrolyzed. The HS pyrolysates changed from isocyanate to amine with increasing temperature. We believe that the newly found pyrolysis behavior of PUEs with different ratios between the HS and SS will promote future studies on the characterization of PUE materials and the pyrolytic recovery of chemical feedstock from PUE wastes.
KW - Fast pyrolysis
KW - Hard and soft segment
KW - In-situ product monitoring
KW - Polyurethane elastomer
KW - Py-GC/MS
KW - Slow pyrolysis
UR - http://www.scopus.com/inward/record.url?scp=85076726742&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85076726742&partnerID=8YFLogxK
U2 - 10.1016/j.jaap.2019.104754
DO - 10.1016/j.jaap.2019.104754
M3 - Article
AN - SCOPUS:85076726742
VL - 145
JO - Journal of Analytical and Applied Pyrolysis
JF - Journal of Analytical and Applied Pyrolysis
SN - 0165-2370
M1 - 104754
ER -