Effect of vinyl content on the viscoelastic properties of polybutadienes and polyisoprenes : monomeric friction coefficient

Abstract The rheological behavior of a series of polybutadienes and polyisoprenes presenting various microstructures has been characterized over a wide range of temperatures. The polybutadienes vary in microstructure from 11% to 84% vinyl content. The viscoelastic coefficients resulting from the time—temperature superposition principle were determined. The Rouse theory modified for undiluted polymers was used to calculate the monomeric friction coefficient, ζ 0 , from the transition zone. We determined that the WLF coefficients are the same, and that ζ 0 is a unique function of ( T − T g ) independently of chain microstructure.