Application of NMR spectroscopy to the characterization of elastomer/filler interactions

Proton spin–spin relaxation time measurements have been performed at 300 and 400 MHz on bound rubber‐filler mixes resulting from the solvent extraction of silica‐filled and silicafilled‐modified polybutadiene, on the one hand, and of carbon black‐filled and carbon blackfilled‐modified styrene butadiene rubber, on the other hand. Two relaxation times are observed for all samples. They are ascribed to the occurrence of tightly and loosely bound rubber components, respectively. The effect of the grafting modification of the fillers on the formation of bound rubber and its two components is discussed.