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Solid‐state NMR relaxometry study of phenolic resins
Author(s) -
Adriaensens Peter,
Rego Robby,
Carleer Robert,
Ottenbourgs Ben,
Gelan Jan
Publication year - 2003
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.1351
Subject(s) - relaxometry , hydrogen bond , materials science , solid state , fourier transform infrared spectroscopy , spin diffusion , relaxation (psychology) , diffusion , solid state nuclear magnetic resonance , carbon 13 nmr , hydrogen , proton nmr , polymer chemistry , chemistry , chemical engineering , nuclear magnetic resonance , thermodynamics , organic chemistry , molecule , spin echo , physics , medicine , psychology , social psychology , magnetic resonance imaging , engineering , radiology
1 H wideline and 13 C CP/MAS spin‐lattice ( T 1H ) relaxation solid‐state NMR experiments have been performed in order to investigate the cure state of phenolic novolac resins. Due to the process of spin diffusion, a single averaged T 1H decay time was found which was sensitive to the cure state of the network structure. Measurements as a function of temperature revealed that mobile end‐groups and branches determine the most efficient pathway of T 1H relaxation. Combined with FTIR measurements, it is shown that rearrangements of the hydrogen bond structure take place upon heating–cooling. There are strong indications that the process of disruption–reformation of the hydrogen bonds is not completely reversible. Copyright © 2003 Society of Chemical Industry