A method for producing a polypropylene-containing composition which includes (a) polymerizing a first quantity of propylene in a first reaction zone in the presence of a first polymerization catalyst to provide a first quantity of polypropylene having a weight- average molecular weight M w,A ; (b) polymerizing a second quantity of propylene optionally mixed with a minor amount of one or more olefins other than propylene in a second reaction zone in the presence of a second polymerization catalyst to provide a second quantity of polypropylene comprising a polypropylene homopolymer or random copolymer and having a weight-average molecular weight M w,B ; and (c) combining the first quantity of polypropylene with the second quantity of polypropylene to form a bimodal polypropylene; wherein the percent by weight of the first quantity of polypropylene in the bimodal polypropylene composition is equal to or greater than 65 percent, and the ratio M w,B /M w,A is at least about 2.