Abstract
The chemical substitution of amine nitrogens in cured, 15N-labeled epoxy resins has been determined by a combination of rotational-echo double-resonance 13C NMR and dipolar rotational spin-echo 15N NMR. Amine-nitrogen substitution is at least 90% (that is, no more than 10% of all nitrogens have a directly bonded hydrogen) for resins formed from stoichiometric amounts of epoxide and either hexamethylenediamine or a 1:3 molar mixture of hexamethylenediamine and hexylamine. This direct measure of curing and cross-linking is consistent with indirect Fourier-transform infrared estimates of curing based on the disappearance of the deformation band of the epoxide ring.
Original language | English (US) |
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Pages (from-to) | 6760-6763 |
Number of pages | 4 |
Journal | Macromolecules |
Volume | 30 |
Issue number | 22 |
DOIs | |
State | Published - Nov 3 1997 |
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry