Method of increasing bubble stability of a polyethylene resin

A method of increasing bubble stability of a needful bimodal high-density polyethylene (HDPE) resin that comprises a higher molecular weight (HMW) polyethylene polymer constituent and a lower molecular weight (LMW) polyethylene polymer constituent and has an overall density from 0.935 to 0.970 gram per cubic centimeter (g/cm3) and an overall weight-average molecular weight (Mw) from 200,000 to 450,000 grams per mole (g/mol), which needful bimodal HDPE resin is in need of increased bubble stability because the properties of the needful bimodal HDPE resin are different than those of a prior resin made in the same reactor due to change in reactor conditions and the needful bimodal HDPE resin has a first melt storage modulus G′ (at loss modulus G″=3000 pascals) of less than 1501 pascals and a first complex viscosity ratio SH1000 of from 33.0 to 49.0, the method comprising:

• contacting under oxygen-tailoring conditions a melt of the needful bimodal HDPE resin with an oxygen-tailoring mixture consisting essentially of a tailoring effective amount of molecular oxygen gas (O2) and one or more inert gases, and wherein during the contacting the melt is at a temperature from 235° to 251° C., so as to make an oxygen-tailored bimodal HDPE resin having a second melt storage modulus G′ (at G″=3000 pascals) of from 1565 to 1900 pascals and a second complex viscosity ratio SH1000 of from 38.0 to 50.0;
• wherein density is measured according to ASTM D792-13, Method B;
• wherein Mw is measured according to the Gel Permeation Chromatography (GPC) Test Method;
• wherein each melt storage modulus G′ (at G″=3000 pascals) is measured according to the Melt Storage Modulus Test Method;
• and
• wherein each complex viscosity ratio SH1000 is equal to Eta*0.10/Eta*100, wherein Eta*0.10 is complex viscosity in pascal-seconds (Pa-s) measured at 0.10 radian per second (rad/s) and wherein Eta*100 is complex viscosity in Pa-s measured at 100 rad/s, both measured according to Dynamic Mechanical Analysis Test Method.