Polyethylene and controlled rheology polypropylene polymer blends and methods of use

A polymer blend comprising 85-99.9 wt % of a metallocene medium density polyethylene (PE) and 0.1-15 wt % of a controlled-rheology polypropylene (CRPP), wherein the CRPP comprises 0.001 wt.% to 5 wt.% of unreacted prodegradant blended therewith and the prodegradant consists of a peroxide compound, wherein the polymer blend has a higher melt strength than the melt strength of the PE absent the CRPP;

• wherein:
• a melt flow rate of the CRPP is 100 from 500 to 1,300 g/10 minutes as measured according to ASTM D1238 at a temperature of 230° C. with a ram weight of 2.16 kg;
• a melt flow rate of the PE is from 3.9 g/10 minutes to 4.6 g /10 minutes as measured according to ASTM D1238 at a temperature of 230° C. with a ram weight of 2.16 kg;
• and
• wherein a melt flow rate of the polymer blend is about the same as the melt flow rate of the PE as measured according to ASTM D1238 at a temperature of 230° C. with a ram weight of 2.16 kg;
• a zero shear viscosity of the polymer blend is increased by a factor of 1.3 to 10 compared to a zero shear viscosity of the PE absent the CRPP;
• and
• a breadth parameter of the polymer blend is reduced by 15% to 40% compared to the PE without the CRPP.