Abstract: According to the contribution of main structural units to the peaks, six equations for diad concentrations in terms of peak intensity have been derived based on the ¹³C-NMR spectrum assignments of hydrogenated styrene-butadiene copolymers (HPBS). Many structural data, including the concentrations of diads, monomer units and their blocks, the number-average sequence lengths of each monomer unit and other structural parameters, were calculated. Basically consistent results from ¹H-and ¹³C-NMR spectra were obtained for the styrene-butadiene copolymers before and after hydrogenation. Furthermore, the correlation between the microstructure of HPBS and its behavior serving as viscosity index improver has been preliminarily investigated. The results would provide a basis for preparation of HPBS with better performance.

Key words: Hydrogenated styrene-butadiene copolymer, NMR spectrum, Sequence distribution, Concentration of structural units