Analyzing the effects of thermal stress on insulator papers by solid-state 13C NMR spectroscopy

AbstractMillion tons of cellulosic paper have been used for insulating coils in oil-filled electrical power transformers, thereby assuring the electricity supply for our societies. The high working temperatures in transformers constantly degrade paper insulators throughout their service life of up to 40 years. We approached the structural changes in oil-immersed cellulosic paper samples upon thermal stress in a study that compared unbleached softwood Kraft paper used as insulator paper with pure cotton cellulose paper. The model experiments used a thermal treatment in transformer oil at 170 °C for up to 14 days. The samples were characterized by means of 13C CP/MAS NMR spectroscopy, mainly based on deconvolution of the C4 resonance. An automated, fast, and reproducible C4 resonance deconvolution employing the “Peak Analyzer” tool of OriginPro 2020 (OriginLab Corporation, USA) was developed and used to exploit 13C CP/MAS NMR spectroscopy for the characterization of thermally stressed paper samples. Our results show that thermally induced structural changes depend heavily on the composition of paper, that hornification and coalescence of fibrils take place, and that the allomorph composition of cellulose crystallites is altered under the given conditions. Graphical abstract

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Determination of the structural changes by Raman and [sup 13]C CP/MAS NMR spectroscopy on native corn starch with plasticizers

10.1063/1.4833692 ◽

2013 ◽

Author(s):

O. Cozar ◽

C. Filip ◽

N. Cioica ◽

C. Coţa ◽

C. Tripon ◽

...

Keyword(s):

Nmr Spectroscopy ◽

Structural Changes ◽

Corn Starch ◽

Mas Nmr ◽

Cp Mas Nmr

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27Al-MAS-NMR-Untersuchungen des thermischen Abbaus von NH4Al(SO4)2·12H2O / 27Al-MAS-NMR Studies on the Thermolysis of NH4Al(SO4)2· 12H2O

Zeitschrift für Naturforschung B ◽

10.1515/znb-1991-1110 ◽

1991 ◽

Vol 46 (11) ◽

pp. 1515-1518 ◽

Cited By ~ 2

Author(s):

Gerhard Wegner ◽

Gert Blumenthal ◽

Dirk Müller ◽

Dirk-Henning Menz ◽

Antje Schmalstieg

Keyword(s):

Nmr Spectroscopy ◽

Structural Changes ◽

Chemical Shifts ◽

Mas Nmr ◽

Nmr Studies ◽

High Stage ◽

27Al Mas Nmr ◽

High Resolution Nmr ◽

First Time

Products of the thermolysis of NH4Al-alum were prepared under dried air and characterized by X-ray powder diffraction, thermogravimetry, and for the first time by solid-state 27Al-MAS-NMR spectroscopy. It was found, that high resolution NMR spectroscopy is applicable to follow up the thermal decomposition and to indicate even minor structural changes. 27Al-MAS-NMR spectra show peaks with characteristic chemical shifts for octahedral Al-units up to a high stage of thermolysis. During the decomposition of Al2(SO4)3 to γ-Al2O3 we again observed three-peak spectra with the specific signal at ≈ 35 ppm for penta-coordinated Al ions as recently proved for the thermolysis of AlCl3 · 6 H2O.

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Interaction of Gold with Co-Condensed and Grafted HMS-SH Silica: A 29Si {1H} CP-MAS NMR Spectroscopy, XRD, XPS and Au LIII EXAFS Study

European Journal of Inorganic Chemistry ◽

10.1002/ejic.201000427 ◽

2010 ◽

Vol 2010 (23) ◽

pp. 3628-3635 ◽

Cited By ~ 4

Author(s):

Valeria La Parola ◽

Alessandro Longo ◽

Anna Maria Venezia ◽

Alberto Spinella ◽

Eugenio Caponetti

Keyword(s):

Nmr Spectroscopy ◽

Mas Nmr ◽

Exafs Study ◽

Cp Mas Nmr

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Cross Polarization/Magic Angle Spinning Nuclear Magnetic Resonance (CP/MAS NMR) Spectroscopy

Methods in Lignin Chemistry - Springer Series in Wood Science ◽

10.1007/978-3-642-74065-7_11 ◽

1992 ◽

pp. 146-161 ◽

Cited By ~ 18

Author(s):

G. J. Leary ◽

R. H. Newman

Keyword(s):

Nuclear Magnetic Resonance ◽

Nmr Spectroscopy ◽

Magnetic Resonance ◽

Magic Angle Spinning ◽

Mas Nmr ◽

Magic Angle ◽

Cross Polarization ◽

Angle Spinning ◽

Cp Mas Nmr ◽

Nuclear Magnetic

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ChemInform Abstract: DYNAMIC INTERMOLECULAR TAUTOMERISM OF 3,5-DIMETHYLPYRAZOLE IN THE SOLID STATE BY CARBON-13 CP/MAS NMR SPECTROSCOPY AND X-RAY CRYSTALLOGRAPHY

Chemischer Informationsdienst ◽

10.1002/chin.198551065 ◽

1985 ◽

Vol 16 (51) ◽

Author(s):

A. BALDY ◽

J. ELGUERO ◽

R. FAURE ◽

M. PIERROT ◽

E.-J. VINCENT

Keyword(s):

Solid State ◽

Nmr Spectroscopy ◽

Mas Nmr ◽

X Ray ◽

X Ray Crystallography ◽

Cp Mas Nmr

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Carbon-13 CP/MAS NMR spectroscopy of magnesium-anthracene and -cyclooctatetraene complexes: graphite-assisted degradation of a magnesium-anthracene complex

Organometallics ◽

10.1021/om00053a007 ◽

1991 ◽

Vol 10 (7) ◽

pp. 2098-2100 ◽

Cited By ~ 11

Author(s):

William M. Brooks ◽

Colin L. Raston ◽

Rodney E. Sue ◽

Frank J. Lincoln ◽

Justin J. McGinnity

Keyword(s):

Nmr Spectroscopy ◽

Mas Nmr ◽

Cp Mas Nmr

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Identification of Copper Binding Sites in Soil Organic Matter through Chemical Modifications and13C CP-MAS NMR Spectroscopy

Environmental Science & Technology ◽

10.1021/es049653w ◽

2004 ◽

Vol 38 (19) ◽

pp. 5059-5063 ◽

Cited By ~ 17

Author(s):

M. Schilling ◽

W. T. Cooper

Keyword(s):

Organic Matter ◽

Nmr Spectroscopy ◽

Soil Organic Matter ◽

Binding Sites ◽

Mas Nmr ◽

Copper Binding ◽

Chemical Modifications ◽

Cp Mas Nmr ◽

Copper Binding Sites

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Polymeric dimethylytterbium and the terminal methyl complex (TptBu,Me)Yb(CH3)(thf)

Chemical Communications ◽

10.1039/d0cc06981g ◽

2021 ◽

Vol 57 (2) ◽

pp. 243-246

Author(s):

Markus M. Katzenmayer ◽

Benjamin M. Wolf ◽

Alexandros Mortis ◽

Cäcilia Maichle-Mössmer ◽

Reiner Anwander

Keyword(s):

Nmr Spectroscopy ◽

Mas Nmr ◽

Elimination Reactions ◽

Cp Mas Nmr ◽

Methane Elimination

Pyrophoric redox-sensitive [YbMe2]n is obtained from [Yb{N(SiMe3)2}2]2 and methyllithium and its existence proven by 171Yb CP/MAS NMR spectroscopy and distinct methane elimination reactions.

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