Polymer waste recycling is becoming a major problem, because huge amounts of synthetic polymers are manufactured every year for many different purposes. Polymer scraps are gathered from the Municipal Solid Waste (MSW). Within those wastes there are several different polyolefins-such as polyethylene, polypropylene, and polystyrene-all incompatible with each other. In order to recycle these polymers, compatibilization of these polyolefins is needed to avoid high sorting costs and unacceptably low market-value products. In this work, the compatibilization of low-density polyethylene with polypropylene is accomplished through the addition of maleated polyethylene and maleated polypropylene. Prediction of the tensile properties of these blends is attempted, using a model based on continuity of phases in a two-components mixture of thermoplastics.