[article]
| Titre : |
Oxidative crosslinking of alkyd resins studied with mass spectrometry and NMR using model compounds |
| Type de document : |
texte imprimé |
| Auteurs : |
W. J. Muizebelt, Auteur ; J. J. Donkerbroek, Auteur ; M. W. F. Nielen, Auteur ; J. B. Hussem, Auteur ; M. E. F. Biemond, Auteur ; R. P. Klaasen, Auteur ; K. H. Zabel, Auteur |
| Année de publication : |
1998 |
| Article en page(s) : |
p. 83-93 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Esters
Huiles et graisses
Oxydation
Polyalkydes
Réticulation (polymérisation)
Spectrométrie de masse
Spectroscopie de la résonance magnétique nucléaire
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
The crosslinking of alkyd resins has been studied using ethyl linoleate and methyl ricinoate as model compounds. With quantitative 13C NMR it was established that ether- and peroxy-crosslinks were formed in roughly equal amounts. Double bonds reacted to give epoxides, endoperoxides, and β-scission into aldehydes. Using SIMS it was established that dimers through pentamers were formed having included several oxygen atoms. After reduction of peroxide (crosslinks) with stannous chloride, the higher oxygen homologues decreased. In the NMR spectrum of the reduced material, peroxide and epoxide signals completely disappeared. High resolution electrospray ionization mass spectra (ESI-MS) yielded evidence regarding the crosslink mechanism. The non-conjugated linoleic acid was found to crosslink by combination of radicals: dimers were having masses 2(M-1). The conjugated linoleic acid crosslinked by addition of radicals to the double bond and disproportionation, yielding masses 2M as well. (M = mass of ethyl linoleate or methyl ricinoate, respectively, including several oxygen atoms.) EIS-MS of oligomers after isotopic exchange enabled estimation of OH and OOH groups. |
| Note de contenu : |
- EXPERIMENTAL : Materials - Crosslinking of ethyl linoleate and methyl ricinoate - Size-exclusion chromatography - Quantitative 13C NMR - Mass spectrometers - Methods
- RESULTS AND DISCUSSION : Oxygen uptake - Size exclusion chromatography - Quantitative 13C NMR - Double bond titration - Mass spectrometry of oligomers - Reduction of peroxides and epoxides with SnCl2 - Electrospray ionization-MS - Exchangeable hydrogen of oligomers - Mechanistic implications - Relevance to coatings systems |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=17959 |
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 70, N° 876 (01/1998) . - p. 83-93
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Oxidative crosslinking of alkyd resins studied with mass spectrometry and NMR using model compounds in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 70, N° 876 (01/1998)
