Nearly half of the global production of thermoplastics are used for packaging material and thus for a single use. 25.2 Mio tons of plastic waste accrued in 2012, 38% were landfilled, 36% were burnt for energy recovery and 26% were mechanically or chemically recycled [1]. Due to the mixed composition of plastic waste, mechanical and chemical recycling are limited. A Separation of the different plastic fractions is expensive and in some cases nearly impossible. But the instantaneous state of the art and the legislation allows a profitable separation of household plastic waste in a PET-fraction, a PS-fraction and a polyolefin fraction (PP, HDPE, LDPE). PP as the most valuable component from the polyolefin fraction can be separated manually to a residual content of PE of 10% [2]. Due to aging, molar mass decreases and mechanical properties deteriorate. In order to compensate resulting negative influences we have chosen branching as method of choice. The chemical modification of PP in melt is a well-studied topic in science and includes melt grafting, branching and crosslinking [3]. Preparing a reference in the present work industrial grain of PP was melt mixed with defined amounts of PE (up to 10% PE impurity) and was melt modified by a reactive extrusion process. Chemical modification was a peroxide induced branching supported by a vinyl-monomer. The so-prepared samples were thermally, thermo-mechanically, mechanically and rheologically characterized to get information about changes in molecular structures and properties. As a result not only a method of recycling is proposed but an upcycling of PP-post consumer waste. [1] PlasticsEurope - Plastics-The facts 2013 [2] Brandrup, J. (1996). Recycling and Recovery of Plastics, Hanser Publishers. [3] Graebling, D. (2002). "Synthesis of Branched Polypropylene by a Reactive Extrusion Process." Macromolecules 35, 4602-4610