High molecular weight multimodal elastomer compositions with good processability

A method for making a reactor blend, the method comprising:

• (a) feeding to a first polymerization reaction zone (i) a plurality of monomers comprising ethylene, one or more C3-C20 α-olefins, and, optionally, one or more non-conjugated polyenes, and (ii) a Ziegler-Natta catalyst system comprising a Ziegler-Natta catalyst and one or more co-catalysts;
• (b) forming, in the first polymerization reaction zone, a first polymer reaction product having Mooney viscosity within a range of 65 to 74 MU (ML, 1+8@150° C.);
• (c) withdrawing a first polymerization reaction effluent comprising at least a portion of the first polymer reaction product from the first polymerization reaction zone;
• (d) providing to a second polymerization reaction zone at least a portion of the first polymerization reaction effluent, ethylene, one or more C3-C20 α-olefins, and, optionally, one or more polyenes;
• (e) forming, in the second polymerization reaction zone, a second polymer reaction product having Mooney viscosity that is at least 150 MU (ML, 1+8@150° C.) greater than the Mooney viscosity of the first polymer reaction product;
• and
• (f) withdrawing from the second polymerization reaction zone a second polymerization reaction effluent comprising the reactor blend;
• wherein the reactor blend comprises an unreacted portion of the first polymer reaction product and the second polymer reaction product, and further has Mooney viscosity within a range from 77 to 87 MU (ML, 1+8@150° C.), and a molecular weight distribution (Mw(LS)/Mn(DRI) within a range from 4 to 7.