Carbon-13 and Proton Nuclear Magnetic Resonance Spectroscopy of Thermosetting Polymers; Analysis of Tetraglycidyl Methylenedianiline/Diaminodiphenylsulfone Formulations
SourceThe proton nuclear magnetic resonance (NMR) spectrum of a tetraglycidyl methylenedianiline/diaminodiphenylsulfone (TGMDA/DDS) mixture contains regions suitable for the quantitative determination of the resin-to-curing agent ratio. This ratio, expressed in parts curing agent per hundred parts resin (phr), may be found from a simple expression relating the areas of the two aromatic proton signal regions. Preliminary results obtained on replicate samples of five known formulations were satisfactory with respect to reproducibility, but showed a -2 phr systematic error at curing agent contents above 30 phr. The method is undergoing refinement.
The carbon-13 NMR spectrum of these formulations also is suitable for quantitative analysis, but a procedure has not yet been developed.