Pure and Applied Chemistry

Abstract: The influence of impact modifiers composed of an elastomer-based core and a poly(methyl methacrylate) (PMMA) shell on the melt flow properties of different thermoplastics has been studied, using both steady-state and dynamic viscosity measurements. The melt viscosities of the rubber-toughened blends were similar to those of the matrix polymers, over the range of shear rates commonly applied during melt processing. In the case of the matrix polymers, viscosity curves obtained under dynamic conditions coincided with those obtained under steady-state conditions. However, for blends the two curves show a slight divergence at low strain rates, where yielding is observed.