Thermal degradation of the polyurethane from 1,4-butanediol and methylene bis(4-phenyl isocyanate)

1978 ◽  
Vol 16 (7) ◽  
pp. 1563-1574 ◽  
Author(s):  
N. Grassie ◽  
M. Zulfiqar
Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3205
Author(s):  
Sanita Reinerte ◽  
Vilhelmine Jurkjane ◽  
Ugis Cabulis ◽  
Arturs Viksna

In this study, rigid polyurethane (PU) and polyisocyanurate (PIR) foam samples made from renewable material (tall oil fatty acid) based polyols were analyzed by pyrolysis gas chromatography mass spectrometry (Py-GC/MS) to obtain information about the full relative smoke content, with a focus on substance identification by their functional groups and hazardousness. The relative content of gaseous products produced during the thermal degradation was evaluated between the two samples, differenced by their assigned isocyanate (NCO) index value—150 and 300. The main thermal degradation components of the rigid PU-PIR foam were found to originate from the decomposition of isocyanate, primarily forming 4,4′-methylenedianiline, 3,3′-diaminodiphenylmethane, N-methylaniline, aniline, 4-benzylaniline and phenyl isocyanate. Hazard analysis revealed that the most common hazards were the hazards related to health: H315 (36%), H319 (28%), H335 (25%), and H302 (23%). The chemical compound with the highest relative content value—4,4′-methylenedianiline (45.3% for PU and 52.4% for PIR)—was identified to be a suspected carcinogen and mutagen. The focus of the study was identifying and evaluating the relative quantities of the produced gaseous products, examine their hazardousness, and provide information on the released thermal degradation products to form a renewable-source based rigid PU and PIR foam.


1981 ◽  
Vol 42 (C1) ◽  
pp. C1-301-C1-307
Author(s):  
I. T. Ritchie ◽  
J. Spitz
Keyword(s):  

Author(s):  
Sh.M. Rakhimbayev ◽  
◽  
T.V. Anikanova ◽  
I.M. Kolesnikov ◽  
◽  
...  

2016 ◽  
Vol 38 (4) ◽  
pp. 302-306
Author(s):  
V.V. Boyko ◽  
◽  
O.A. Radchenko ◽  
S.V. Riabov ◽  
S.I. Sinelnikov ◽  
...  

2013 ◽  
Vol 56 (4) ◽  
pp. 133-135
Author(s):  
Yuki IKEDA ◽  
Satoru IWAMORI ◽  
Hiroyuki MATSUMOTO ◽  
Kiyoshi YOSHINO ◽  
Itsuo NISHIYAMA ◽  
...  

Author(s):  
P. Singh ◽  
G.T. Galyon ◽  
J. Obrzut ◽  
W.A. Alpaugh

Abstract A time delayed dielectric breakdown in printed circuit boards, operating at temperatures below the epoxy resin insulation thermo-electrical limits, is reported. The safe temperature-voltage operating regime was estimated and related to the glass-rubber transition (To) of printed circuit board dielectric. The TG was measured using DSC and compared with that determined from electrical conductivity of the laminate in the glassy and rubbery state. A failure model was developed and fitted to the experimental data matching a localized thermal degradation of the dielectric and time dependency. The model is based on localized heating of an insulation resistance defect that under certain voltage bias can exceed the TG, thus, initiating thermal degradation of the resin. The model agrees well with the experimental data and indicates that the failure rate and truncation time beyond which the probability of failure becomes insignificant, decreases with increasing glass-rubber transition temperature.


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