Compatibilization of Recycled Polypropylene with Polyethylene Blends Via Ionic Liquid to Enhance Mechanical Properties

Polypropylene (PP) is the world's second-largest plastic resin based on production volume, after polyethylene (PE). In 2021, the global production volume of PP amounted to 80 million tons. Less than 2% of total produced PP is recycled annually. PP is sensitive to mixed polymers, and a minor amount of other polymeric contaminants reduces physical properties (Figure 1). To increase the recyclability of PP, there is a specific need to have additives that upcycle. PP represents the most significant opportunity in increasing recycling rates. Ionic liquids (ILs) are universal solvents and can promote compatibilization among different polymers. RoCo has developed several ILs that are non-toxic, and when mixed with polyolefins, they enhance the dispersion of fillers and improve mechanical properties thus opening doors to upcycling of recycled polymers. We have been evaluating the recycling of PP by using ionic liquids. We will be sharing our data on ILs compatibilizer results in retaining and enhancing the mechanical properties of PP even when mixed with 15% PE. Both the tensile and impact properties were improved resulting in upcycling of PP. We are in the process of investigating additional properties such as conductivity and surface properties.