High Resolution Solid-13C-NMR-Spectroscopy of Elastomers.

Though line broadening occurs in solids, **1**3C-NMR resolution is sufficient to identify elastomers of one or two raw rubbers, e. g. CR/NR, CR/CSM, NR/CSM. Analysis of ternary blended NR/SBR/BR is discussed. Fillers including carbon black, accelerators and antioxidants do not interfere, however, greater amounts of plasticizers have to be extracted. Swelling in 1,1,2,2-tetrachloroethane reduces the linewidth and increases the information. The type of NBR can be determined by identifying the sequences of acrylonitrile and butadiene. The crosslink density of ebonite is too high so that distinct resonances are not resolved. The study of swollen intermediate samples revealed the formation of trans-structures.