Synthesis of polyesters as binders for deinkable inks. VI. Structural analysis of the copolyesterification between o-phthalic anhydride, oleic acid, and trimethylolpropane in bulk at 160°C by high resolution 13C- and 1H nuclear magnetic resonance (13C- and 1H-NMR)
✍ Scribed by M. M. C. López-González; M. J. Callejo Cudero; J. M. Barrales-Rienda
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 374 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0887-624X
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✦ Synopsis
A detailed structural analysis of the copolyesterification in bulk without any external catalyst at 160ЊC between o-phthalic anhydride (P), oleic acid (O), and trimethylolpropane (T) with a mol ratio ([{COOH]/[{OH]) Å 0.70 has been carried out by high resolution 13 C nuclear magnetic resonance ( 13 C-NMR) (DMSO-d 6 and CDCl 3 solutions), 1 H nuclear magnetic resonance ( 1 H-NMR) (CDCl 3 solution), and by volumetry. The use of CDCl 3 as NMR solvent has allow us to identify several signals that have been assigned to trimethylolpropane monoesters with different esterification degrees in the o-phthalate residue. Identically, we have detected signals assignable to monoesters at the chain ends in structures with different chain lengths. These monoesterified structures have been also confirmed by analyzing samples modified by the diazomethane addition. These modified samples have been also used to determine free acid groups as their methoxylic derivatives by 1 H-NMR in CDCl 3 solution. We have not observed any detectable signs of gelation nor products produced by secondary reactions.