Viscosity predictions for model miscible polymer blends: Including self-concentration, double reptation, and tube dilation

The viscosities of miscible blends of 1,4-polyisoprene ( M n = 78 kg ∕ mol ) /poly(vinylethylene) ( M n = 10 kg ∕ mol and 120 kg ∕ mol ) and polystyrene ( M n = 30 kg ∕ mol ) /poly(vinyl methyl ether) ( M n = 105 kg ∕ mol ) were measured as a function of temperature and composition. These results, along with literature data for poly(ethylene-alt-propylene)/head-to-head polypropylene [Gell (1996)] and molecular weight blends of 1,4-polybutadiene [Wang et al. (2003)], were compared to the predictions of a previously published model [Haley and Lodge (2004a)]. The agreement between theory and experiment is generally good, though some quantitative discrepancies are apparent. A new tube dilation model that predicts the terminal relaxation time of the slower moving component in a blend as a function of composition is presented. This model enables improved viscosity predictions, and in several cases produces near quantitative predictions.