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Determination of methylene bridge type of mixed meta and para‐cresol–formaldehyde novolaks by 13 C‐NMR spectroscopy
Author(s) -
Fitzgerald E. A.,
Tadros S. P.,
Almeida R. F.,
Sienko G. A.,
Honda K.,
Sarubbi T.
Publication year - 1992
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1992.070450219
Subject(s) - methylene , formaldehyde , methylene bridge , chemistry , phenol , infrared spectroscopy , polymer chemistry , oligomer , organic chemistry , materials science
Cresol–formaldehyde resins are important components of photoresists for semiconductor fabrication. The type of methylene bridge and relative amounts thereof are key structural features that determine resin properties. Several model compounds were prepared that represent the various types of methylene bridges that are possible from condensation of meta‐ and para‐cresol with formaldehyde. The methylene bridges were characterized by 13 C‐NMR spectroscopy, and the assignments made were used to analyze spectra of cresol–formaldehyde novolak resin and several oligomer types. The effect of complexation with metal ion on the methylene bridge chemical shift was investigated for one oligomer. The effect of bridging position on the intramolecular hydrogen bonding of the phenolic hydroxyl group was investigated by infrared spectroscopy.