Abstract: Method and systems for online analysis of a polymeric material within a mixing device are provided. In certain embodiments, the methods and systems subject the polymeric material to Raman spectroscopy analysis. The Raman spectroscopy provides analysis of polymer properties that may include melt index, density, viscosity, molecular weight, molecular weight distribution, weight ratios of different polymers comprising the polymeric material, additive concentrations, crosslinking agent concentrations, scissoring agent concentrations, and combinations thereof. The spectroscopy results can be used to provide process control to adjust operating parameters of the mixing device and/or an associated polymerization process. The mixing device may be an extruder. The methods and systems may also include a processor for evaluating the results of the Raman analysis and automatically adjusting the mixing device and/or polymerization processes.

Abstract: Methods of tailoring polyethylenes are contemplated utilizing 0.5 to 7.95 volume percent oxygen containing gases. The tailoring occurs in a melt-conveying zone of a mixer/extruder, and not in the feed or melting zones of a mixer/extruder. The effect of tailoring is to increase elasticity (G?/G?) of the polyethylenes more than 10 percent over similar polyethylenes that are extruded/mixed in the substantial absence of oxygen of oxygen containing gases.

Abstract: Melt fracture is reduced, without the necessity of polymer processing-aid additives specifically designed to alleviate exit region surface melt fracture phenomenon, by heating at least a portion of the die through which the polymer is extruded. The die exit region is maintained at a temperature above the bulk melt temperature of the polymer extruded through the die exit hole.