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Hydrogenation of low‐molar‐mass, OH‐telechelic polybutadienes. II. Nuclear magnetic resonance and infrared spectrometric determination of hydroxyl end groups before and after hydrogenation by diimide
Author(s) -
Podešva J.,
Spěváček J.,
Dybal J.
Publication year - 1999
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/(sici)1097-4628(19991220)74:13<3214::aid-app25>3.0.co;2-a
Subject(s) - molar mass , end group , titration , proton nmr , chemistry , polymer chemistry , infrared , diimide , telechelic polymer , acetic anhydride , polymer , analytical chemistry (journal) , organic chemistry , copolymer , molecule , physics , perylene , optics , catalysis
1 H nuclear magnetic resonance ( 1 H‐NMR), 13 C‐NMR, and infrared spectroscopies were used to determine concentrations ( c OH , in mmol/g) of the secondary hydroxyl end groups in the low‐molar‐mass, OH‐telechelic polybutadienes, and their hydrogenated analogs. Mean OH‐functionality ( f OH ≤ 2), that is, an average number of OH groups per one polymer chain, was calculated from c OH for each sample and each method, and the results were compared with those obtained by a conventional acetic anhydride titration method. It has been found that with molar masses of the samples studied (2310 to 3410 g/mol), the differences between individual spectrometric methods are usually not higher than approximately 10%, which corresponds to an expected relative experimental error. Certain differences in f OH between individual methods are discussed. No systematic change of f OH after virtually total hydrogenation of the olefinic double bonds of the polymeric substrate by diimide was observed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3214–3224, 1999