On the molecular orientation of polyethylene terephthalate

Baranova, S. A.; Gribanov, S. A.; Klyushnik, B. N.; Пахомов, П. М.; Geller, V. E.; Shablygin, M. V.

doi:10.1016/0032-3950(83)90209-5

Cited by 4 publications

(1 citation statement)

References 11 publications

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“…(), small peaks at around 800 cm −1 region could be assigned to mineral impurities (silicates), and small peaks at 845 cm −1 (observed in cuticles) could tentatively be assigned to methylene (CH 2 ) vibrations (Baranova et al . , ; Trachuk ), although the contribution of some remaining organic matter should not be ruled out. Our results show more similar peaks for leaf compressions than to isolated cuticles as recorded by Zodrow et al .…”

Section: Resultsmentioning

confidence: 99%

Fourier transform infrared characterization of the Middle Devonian non‐vascular plant Spongiophyton

2016

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Spectroscopy information (functional groups and semiquantitative data) by Fourier transform infrared (FTIR) spectroscopy of Spongiophyton Kr€ ausel emend. Chaloner et al. is reported for the first time, in an attempt to identify spectroscopic patterns that would differentiate species of these taxa. A total of 33 specimens identified as S. lenticularis, S. nanum and S. minutissimum and preserved as compressions were analysed. They come from the same fossiliferous horizon of one outcrop situated in the uppermost Middle Devonian São Domingos Formation of the Paran a Basin in southern Brazil. The results reveal that functional groups in the 3000-2800 and 1800-700 cm À1wavenumber regions are present in all specimens. Infraredderived ratios (CH 2 /CH 3 , Al/Ox, Ox1/Ox2, C=O cont., C=C cont., Al2 and Ar/Al) and types of kerogen led to a comparison of the morphological characteristics of the studied material and indicate that compressions of S. lenticularis, S. nanum and S. minutissimum contain different organic compounds. S. nanum and S. minutissimum show higher oxidation and lower aromaticity of its organic matter than S. lenticularis. Additionally, S. lenticularis shows low A-factor values, suggesting a composition similar to type III kerogen, while S. nanum and S. minutissimum showed intermediate to high A-factor values, suggesting a composition similar to type II kerogen. In conclusion, the chemical-analytical techniques and statistical analysis (using PCA technique) reveal a closer taxonomic relationship between S. nanum and S. minutissimum than either has with S. lenticularis, supporting their taxonomic separation, previously proposed in the literature on the basis of morphological features. Lastly, the chemical signatures support the hypothesis that links these enigmatic fossils to a type of lichen or other early inland plant.

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Section: Resultsmentioning

confidence: 99%

Fourier transform infrared characterization of the Middle Devonian non‐vascular plant Spongiophyton

2016

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Infrared spectra of poly(ethylene terephthalate) yarns. Fitting of spectra, evaluation of parameters, and applications

Heuvel

Huisman

1985

J of Applied Polymer Sci

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synopsisA quantitative model for fitting infrared spectra of polyethyleneterephthalate samples over the region from 1100 to 720 cm-l has been evaluated. The absorbance was described as the sum of a linear base line and a set of symmetrical bell-shaped Pearson VII curves. Using this model, experimental transmission spectra of yams, measured with the electric vector parallel and perpendicular to the fiber axis, were fitted. It was found that each of the trans bands near 972 and 845 cm-' consists of two components, a narrow and a broad one. These two components represent the crystalline and amorphous phases respectively. The band due to the out of plane benzene ring C-H deformation vibration at about 875 cm-l appeared also to be composed of two contributions. In this case, the narrow component was found to be due to molecules having interactions with direct neighbors. So this narrow component not only contains the molecules in the crystalline phase but also those forming part of bundles which are too small to be detected by x-ray diffraction. For a detailed insight into the molecular arrangement of the amorphous regions, the infrared detection of tmns-guache transitions, fold content, detection of bundlelike structures, and molecular stress on tie molecules turned out to be of great practical importance. The structural details, which can be revealed by the infrared technique, cannot be obtained by other means. The potential of the method is illustrated with some practical examples.

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