Solid State 13C NMR Applied to Styrene-Butadiene Rubbers Study of the Rubber Vulcanized Network Structures

Abstract This paper discusses the structural changes that occur during the accelerated sulfur vulcanization of styrene-butadiene rubbers (SBR) through characterization of the network sulfide structures influenced by the curing agent concentration, the polymer microstructure, and the nature of the filler. Magic angle spinning (MAS) 13C FT - NMR spectroscopy was used to investigate the chemical crosslink properties of unfilled vulcanized SBR in addition to carbon black and silica filled polybutadiene rubber (BR), SBR, and 1:1 BR / SBR blends. New resonances in the 13C NMR spectrum are assigned to the various sulfide crosslink structures in SBR. Structural changes during vulcanization are also discussed.