The present invention relates to polymer blend that includes (a) 50 to 90 percent by weight of a first elastomeric polymer having a high molecular weight, (b) 5 to 50 percent by weight, preferably 5 to 40 percent by weight, more preferably 10 to 35 percent by weight, of a second elastomeric polymer having a low molecular weight and being coupled, wherein the amounts of the components (a) and (b) are based on the total weight of the polymer blend.