The long-term objective is to construct a framework for the less studied correlation between the morphology of a polymer blend and its mechanical or in general performance properties in view of circularity. The framework will form the basis for the development of an effective recycling route for polymer blends and will also be applied for the blending of synthetic and natural polymers. The aim is to develop (i) an effective recycling of synthetic commodity polymers with enhanced mechanical properties, and to enable (ii) effective blending of natural and synthetic polymers with high recyclability. This is done by focusing on two commodity polymers (PP and PE) and on two promising natural polymers being starch and chitosan. The novelty lies in (i) the fundamental incorporation of all relevant processing parameters and their interaction, and (ii) the implementation of reactive extrusion (REX) to develop compatible blends of natural and synthetic polymers aiming at more than 60 wt% of the natural component in the blend with the polyolefin. The project will rely on key fundamental knowledge and simulation-guided process design. Benefiting from the leading expertise of LCT (promotor: Prof. Dagmar R. D’hooge), the connection with material validation at CPMT (promotor: Prof. Mariya Edeleva), and a research stay abroad with Prof. Charitidis, this project displays a high success rate potential.