Some thermodynamic aspects of the thermal degradation of wholly aromatic polyamides

Bhuiyan, Abdul L.

doi:10.1016/0014-3057(83)90126-x

Cited by 6 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Table 4 , the clear difference between the pyrolyzate yields from PBIA, PPTA and PMIA can be discerned, which indicates specific effects of the distinctive heterocyclic ring structure in the PBIA backbone. The obtained data of PMIA fiber and PPTA fiber are found to Brought to you by | Western University Authenticated Download Date | 6/7/15 10:57 AM be consistent with the mechanism previously proposed by Bhuiyan and Broadbent [23,24] .…”

Section: Thermal Degradation Behavior In Nitrogensupporting

confidence: 89%

The thermal degradation behavior of meta- and para- hetero-amide fibers by TGA-FTIR

Sun¹,

Liang²,

Xu³

et al. 2013

Journal of Polymer Engineering

View full text Add to dashboard Cite

The thermal degradation behaviors of polyp-phenylene-benzimidazole-terephthalamide (PBIA), poly-m-phenylene isophthalamide (PMIA) and poly-pphenylene terephthalamide (PPTA) fibers are investigated by thermogravimetric analysis (TGA) coupled with Fourier transform infrared spectroscopy (TGA-FTIR). The results demonstrate that PBIA fiber exhibits better thermal-and thermo-oxidative stability than that of the other two polymers. PBIA shows the highest onset degradation temperature, both in nitrogen and air. TGA-FTIR provides information on compositions of pyrolyzates and their relationship with the structures of polyamides. Analysis of the compositions and distributions of all pyrolyzates, at different temperatures, indicates that a hydrolytic mechanism plays a leading role at lower temperature, and a homolytic mechanism is dominant at higher temperature.

show abstract

Section: Thermal Degradation Behavior In Nitrogensupporting

confidence: 89%

The thermal degradation behavior of meta- and para- hetero-amide fibers by TGA-FTIR

Sun¹,

Liang²,

Xu³

et al. 2013

Journal of Polymer Engineering

View full text Add to dashboard Cite

show abstract

“…It was reported that the scission of NH in the thermal degradation of p-aramid is both thermodynamically and kinetically favorable [140]. An early report on the thermal degradation of different kinds of aromatic polyamides led to the conclusion that it occurred via the hydrolysis of amide bonds whereby water was generated with acid end groups and generated during the dehydration of other groups [141]. Another study suggested the possibility of bond cleavages and free radical intermediates as being the major degradation reaction.…”

Section: Synthesismentioning

confidence: 99%

Thermal Degradation and Fire Behavior of High Performance Polymers

2019

View full text Add to dashboard Cite

show abstract

Studies on the thermal degradation of aromatic polyamides by pyrolysis‐field ionization mass spectrometry and pyrolysis‐gas chromatography

Schulten

Plage

Ohtani

et al. 1987

Angew. Makromol. Chem.

View full text Add to dashboard Cite

The thermal degradation of aromatic polyamides such as poly-(1 ,Cphenyleneterephthalamide) (Kevlar) and poly-(l,3-phenylene-isophthalamide) (Nomex) was studied by pyrolysis-field ionization mass spectrometry (Py-FIMS) and pyrolysis-gas chromatography (Py-GC). In Py-FIMS, the thermal degradation products were recorded which were formed in the ion source of a double focusing mass spectrometer. Usually a temperature range from 50 to 75OOC and a heating rate of 1.2OC/s were employed. Various common and characteristic products for the two samples, respectively the corresponding para-or meta-isomers, were observed up to m/z 500 with significant differences in intensity. The main products observed were produced by both radical homolytic and hydrolytic decompositions.On the other hand, in flash Py-GC the instantaneous thermal degradation products at 720 "C were gas-chromatographically separated by a fused-silica capillary column and detected both by a flame ionization detector and a mass spectrometer with electron ionization @I). Although many of the degradation products were identical with those observed by Py-FIMS, the former almost entirely consisted of the fragments formed through radical homolytic degradation. In general, the differences between the samples with Py-GC were much less than those observed in Py-FIMS. ZUSAMMENFASSUNG:Der thermische Abbau von aromatischen Polyamiden wie Kevlar (Poly-l,4-(phenylen-terephthalamid)) und Nomex (Poly-( 1,3-phenylen-kophthalamid)) wurde mit Pyrolyse-Feldionisation-Massenspektrometrie (Py-FIMS) und Pyrolyse-Gaschromatographie (Py-GC) untersucht. Bei den Messungen mit Py-FIMS wurden die Proben in der Ionenquelie eines doppel-fokussierenden Massenspektrometers im Tempe-raturbereich von 50°C bis 750°C bei einer Heizrate von 1,2 "C/s pyrolysiert. Zahlreiche gemeinsame und charakteristische Abbauprodukte der beiden Proben, bzw. der entsprechenden para-und meta-Isomeren, wurden im Massenbereich bis m/z 500 gefunden, allerdings mit erheblichen Intensitiitsunterschieden. Die Hauptprodukte wurden durch homolytische Reaktionen sowie durch Hydrolyse gebildet .Andererseits wurden die bei 720 "C gebildeten thermischen Abbauprodukte gaschromatographisch mit einer gebundenen Silicagel-Siiule getrennt. Der Nachweis erfolgte sowohl durch einen Flammenionisations-Detektor als auch durch Elektronen-stol3-@I)-Massenspektrometrie. Obwohl viele der Abbauprodukte mit denen der bei den Py-FIMS Messungen gefundenen iibereinstimmten, setzten sich erstere vorwiegend aus solchen Produkten zusammen, welche durch radikalische, homolytische Reaktionen gebildet werden. Die Unterschiede zwischen der Zusammensetzung der thermischen Abbauprodukte der beiden Proben waren allgemein mit Py-GC erheblich geringer, als bei Py-FIMS beobachtet wurde.

show abstract

Some thermodynamic aspects of the thermal degradation of wholly aromatic polyamides

Cited by 6 publications

References 2 publications

The thermal degradation behavior of meta- and para- hetero-amide fibers by TGA-FTIR

The thermal degradation behavior of meta- and para- hetero-amide fibers by TGA-FTIR

Thermal Degradation and Fire Behavior of High Performance Polymers

Studies on the thermal degradation of aromatic polyamides by pyrolysis‐field ionization mass spectrometry and pyrolysis‐gas chromatography

Contact Info

Product

Resources

About