Thermal and thermo-oxidative stability and probable degradation mechanism of some polyetherimides

Lisă, Gabriela; Hamciuc, Corneliu; Hamciuc, Elena; Tudorachi, Niță

doi:10.1016/j.jaap.2016.01.012

Cited by 34 publications

(25 citation statements)

References 28 publications

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“…The consumption of C-H bonds is explained both by the release (in the form of methane) of CH 3 groups from the isopropylidene unit due to the thermolytic cleavage of the C-CH 3 bonds [1,[6][7][8], but also by the preferential propagation of oxidation on the CH 3 groups. Indeed, let us recall that the dissociation energy of a C-H bond is much lower in a CH 3 group (≈ 414 kJ mol −1 ) than in an aromatic ring (≈ 465 kJ mol −1 ).…”

Section: Resultsmentioning

confidence: 99%

“…Mechanisms of chain scission were also proposed to explain the formation of the wide variety of volatile products. Chain scissions occur at the C-C bonds of the isopropylidene unit, but also at the ether bonds between the phenyl and phthalimide rings [1,[6][7][8][9]. They predominate largely over crosslinking at the beginning of exposure, but they become finally negligible in comparison to crosslinking at longer term [1,5,7,10,11].…”

Section: Introductionmentioning

confidence: 99%

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Multi-scale and multi-technical analysis of the thermal degradation of poly(ether imide)

Courvoisier

Bicaba

Colin

2018

Polymer Degradation and Stability

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. A B S T R A C TThe thermal degradation of PEI has been studied in wide ranges of temperature (between 180 and 250°C) and oxygen partial pressure (between 0.21 and 50 bars). On one hand, the chemical ageing mechanisms have been analysed and elucidated by FTIR spectrophotometry and by differential calorimetry (DSC) on sufficiently thin PEI films (between 10 and 60 μm thickness) to be totally free of the effects of oxygen diffusion. As expected, and by analogy with other aromatic polymers of similar chemical structure, oxidation occurs preferentially on the methyl groups of the isopropylidene unit of the bisphenol A part, thus causing the disappearance of their characteristic IR absorption band at 2970 cm −1 and the growth of a new IR absorption band at 3350 cm −1 , attributed to alcohols. In addition, oxidation leads successively to a relative predominance of chain scissions and crosslinking, resulting in a non-monotonic change of T g . On the other hand, the consequences of oxidation on the elastic properties have been analysed and elucidated by micro-indentation on polished cross-sections of PEI plates of 3 mm thickness. The diffusion control of oxidation leads to the development of profiles of Young's modulus within the sample thickness, which correlate perfectly with the changes in chemical structure determined by FTIR spectrophotometry. However, the increase in Young's modulus in the superficial oxidized layer is not the direct consequence of oxidation but of a physical ageing.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Multi-scale and multi-technical analysis of the thermal degradation of poly(ether imide)

Courvoisier

Bicaba

Colin

2018

Polymer Degradation and Stability

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“…The absorbance of C=O group was converted to the concentration using a molar absorptivity of 300 L. mol −1 . cm −1 at the peak position (1,780 cm −1 ) and a molar absorptivity of 42 L.mol −1 . cm −1 at the peak position (2,923 cm −1 ).…”

Section: Methodsmentioning

confidence: 98%

Thermal aging effects on overall mechanical behavior of short glass fiber‐reinforced polyphenylene sulfide composites

Zuo

Fitoussi

Shirinbayan

et al. 2018

Polymer Engineering & Sci

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In this article, the overall mechanical properties of a short glass fiber‐reinforced polyphenylene sulfide (PPS) composite were tested after oxidation at different temperatures (140, 160, 180, and 200°C), with a maximum oxidation time of approximately 5,300 h. In aspect of thermal aging process, the oxidation rates in 200 and 180°C are considerably harsher and faster than the case in 160 and 140°C, according to the concentration evolution of [C=O]. In aspect of mechanical properties, for virgin samples, due to an excellent fiber–matrix adhesion, no progressive damage is developed. Moreover, the fatigue results of aged samples show that the fatigue lifetime of PPS composites decreases more and more obviously with the oxidation time increasing while no significant loss of stiffness is observed. In addition, both monotonic and cyclic loadings are basically driven by the PPS matrix deformation. In the end, the relationship between fatigue lifetime and concentration of [CO] is built and discussed. POLYM. ENG. SCI., 59:765–772, 2019. © 2018 Society of Plastics Engineers

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“…As displayed in Figure and Table , poly(ether imide)s were mainly showed in multiple‐step degradations between 100 and 600 °C. In addition, the main decomposition of poly(ether imide)s occurred approximately around at 430 °C and weight loss in the range from the room temperature to 150 °C could be attributed to the solvent trapped and the water from imidization in poly(ether imide)s …”

Section: Resultsmentioning

confidence: 99%

Synthesis, optical, and thermal properties of polyimides containing flexible ether linkage

Kaya

Kamacı

2018

J of Applied Polymer Sci

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The goal of this article was to synthesize a series of flexible polyimides containing ether linkage in main chain and clarified the effect of this ether linkage on some physical properties such as optical and thermal decomposition. Also, different functional group effects such as carbonyl (CO), hexa‐fluoro‐isopropylidene [C(CF3)2] and phenyl (C6H5) on these physical properties were evaluated. The structural characterization of poly(ether imide)s was performed using Fourier transform infrared, 1H‐nuclear magnetic resonance (NMR), and 13C‐NMR techniques. Optical band gap of polyimides was calculated in the range from 2.57 to 2.81 eV. Thermal characterization of poly(ether imide)s was carried out using thermogravimetry–differential thermal analysis and differential scanning calorimetry. Thermal stability of poly(ether imide)s was evaluated by initial decomposition temperature (Ton) and char. Ton value of polymers was determined in the range from 100 to 195 °C. In addition, glass transition temperatures of poly(ether imide)s were found between 144 and 148 °C. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46573.

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Thermal and thermo-oxidative stability and probable degradation mechanism of some polyetherimides

Cited by 34 publications

References 28 publications

Multi-scale and multi-technical analysis of the thermal degradation of poly(ether imide)

Multi-scale and multi-technical analysis of the thermal degradation of poly(ether imide)

Thermal aging effects on overall mechanical behavior of short glass fiber‐reinforced polyphenylene sulfide composites

Synthesis, optical, and thermal properties of polyimides containing flexible ether linkage

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