Rheological and mechanical properties of gum and filled blends of acrylaterubber and fluororubber

Rheological, mechanical and dynamic mechanical thermal properties of gum an d filled acrylate rubber (ACM), fluoro rubber (FKM) and their blends were s tudied. The systems exhibited pseudo plastic flow behaviour. The shear visc osity of the blends decreased with higher concentration of ACM. There was l ittle effect of temperature on the viscosity of the blends at different she ar rates. Addition of filler to the 50/50 (w/w) ACM/FKM blend increased the shear viscosity. The equilibrium die swell decreased with increasing loadi ng of carbon black and was affected by the filler type. A linear generalize d relationship was obtained between die swell and maximum recoverable defor mation. The activation energy of the melt flow process decreased with an in crease in shear rate for all the gum and filled systems except neat ACM, wh ere there was a slight increase in activation energy. The mechanical proper ties of the filled compounds improved linearly with filler loading. Tan del ta peak temperature did not change with filler loading although the values of tan delta (maximum) decreased. The storage modulus of the blends increas ed with increasing filler loading, indicating the presence of polymer fille r interactions.