Peroxide modified PP/PE blends with superior melt strength

摘要

The instant invention is directed to a process for preparing peroxide modified polypropylene/polyethylene blends that have superior extrusion coating properties. More specifically, the peroxide modified PP/PE blends produced by the instant invention exhibit a pronounced viscosity upturn at low frequencies (about 1.0 rad/sec) in the dynamic rheological data. Specifically, the blends show an increase in their dynamic complex viscosity, &eegr;*, and dynamic storage modulus, G' values at frequencies of less than about 1.0 rad/sec. The present invention also relates to peroxide modified PP/PE blends that are produced from the process of the instant invention. Such polymeric blends that are produced from the inventive method exhibit superior dynamic theological properties, especially melt strength, compared with prior art blends. Moreover, the peroxide modified PP/PE blends of the present invention show markedly reduced draw resonance behavior. Thus, the PP/PE blends of the present invention having the above-identified characteristics will be suitable for a wide variety of applications, such as thermoforming, blow molding and, preferably, extrusion coatings.