English Abstract
Structural Characterization of Vulcanized Natural Rubber by Latex State 13C NMR Spectroscopy
Toyo Tire & Rubber, Co., Ltd, Ibaraki, Osaka, Japan,
Department of Chemistry, Faculty of Engineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
Nippon Gomu Kyokaishi,(2006),79(12),562-566 General Review in Japanese

Crosslinking point is one of important factors that govern mechanical properties of vulcanized elastomers. The method of how to
characterize the crosslinking points through latex state 13C NMR spectroscopy was proposed for vulcanized NR instead of long
standing solid state 13C NMR spectroscopy. Small signals at 44 ppm and 58 ppm in the aliphatic carbon region, which appeared
after vulcanization, were assigned by Distortionless Enhancement by Polarization Transfer (DEPT) and Attached Proton Test (APT) to
secondary, tertiary and quaternary carbons of crosslinking points, respectively. The latex state 13C NMR spectroscopy was proved
to be indispensable to characterize the vulcanized NR.

Natural Rubber, Latex, Structural Characterization, NMR, Rubber Vulcanizate