Some considerations concerning the dynamic mechanical properties of cured styrene-butadiene rubber/polybutadiene blends

The dynamic mechanical response of several binary mixtures of a styrene-but adiene copolymer and high cis-polybutadiene has been studied. The loss tang ent and shear modulus were measured with a free damping torsion pendulum at temperatures between 143 and 343 K in argon atmosphere. From the loss tang ent data the glass transition temperature of each sample was evaluated. The results can be represented by the Fox equation that relates the glass tran sition temperature of the blend with that of constituent polymers. The infl uence in the loss tangent data of the crystallization of the high cis BR us ed in the blend is discussed. A study of the separation of the crystalline and amorphous parts in the polybutadiene using the storage modulus data is presented. Finally, the loss of crystallinity at different contents of SBR in the blend is analysed using the dynamic mechanical data. (C) 2000 Societ y of Chemical Industry.