Recycling Plastic Waste by Solid Phase Mixing

The global plastics problem poses significant environmental, energy, and
climate challenges. Various innovative strategies have been proposed for recycling plastics,
either in open or closed loops, each addressing different aspects of the problems hindering
the achievement of a circular economy. Amidst these efforts, the reuse of mixed plastic waste
still remains a particular challenge, arising from immiscibility, resulting in materials with
suboptimal properties. In this context, we report a novel recycling strategy based on high-
pressure solid-phase mixing of plastic wastes, ensuring the conversion of a binary immiscible
polymer mixture into a mixture consisting entirely of the polymer−polymer interphase. The
proposed recycling strategy represents a significant advancement as it allows for the
production of mixtures with enhanced mechanical properties, all while avoiding the
degradation of the initial molecular weight of the polymeric components. The demonstrated
effectiveness spans a range of immiscible polymer pairs, including polyolefins, polystyrene,
and polyesters, which collectively constitute about 70% of mixed plastic waste.