Spectroscopic Studies of the Structures of Butyl and Bromobutyl Rubbers

Abstract

Abstract The 1 H-NMR results show that the majority of the isoprene units of butyl rubber are incorporated in 1,4 addition. Approximately 6% of the isoprene units undergo 1,2 enchainment. Based on our study of blends of polyisoprene with polyisobutylene, 1 H-NMR provides an excellent method for determining isoprene unsaturation in butyl rubber. Furthermore, based on 1 H-NMR measurement, FTIR procedures have been developed to quantify the isoprene content of butyl polymers and the concentrations of the three major bromobutyl isomers.