Characterization of Modified Natural Rubber through NMR Spectroscopy

Abstract

Characterization of modified natural rubber has been performed through ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy. Recently, pulsed-field-gradient (PFG) technique made possible to observe a correlation between ¹H and ¹³C in good signal to noise ratio in a short time. In fact, 2D NMR measurements with inverse pulse techniques provide a new insight into assignments of signals in NMR spectrum for epoxidized natural rubber, so that the signals are correctly assigned with various pulse sequences. Carbonated natural rubber, which is a novel functional organic material, is characterized through 2D NMR spectroscopy with various pulse techniques, in which no model compound is required for the assignments. Quantitative analysis for a reaction between epoxidized natural rubber and poly (L-lactide) is performed on the basis of the correct assignments of the signals in ¹H NMR spectrum for epoxidized natural rubber. The assignments and related quantitative analysis will play an important role in a molecular design of the modified natural rubber.