Several concurrent developments are shaping the future of plastics. A transition to a sustainable plastics system requires not only a shift to fossil-free feedstock and energy to produce the carbon-neutral building blocks for polymers used in plastics, but also a rational design of the polymers with both desired material properties for functionality and features facilitating their recyclability. Biotechnology has an important role in producing polymer building blocks from renewable feedstocks, and also shows potential for recycling of polymers. Here, we present strategies for improving the performance and recyclability of the polymers, for enhancing degradability to monomers, and for improving chemical recyclability by designing polymers with different chemical functionalities. Rational polymer design is important for desired functionality and recyclability.Increasing the glass transition temperature is an effective strategy for enhancing the performance and recyclability of biobased polymers.Selective polymer depolymerization and repolymerization of monomers offers an important route to plastic recycling.Microbial cells and enzymes constitute important tools for the production as well as recycling of polymers.Feedstock sustainability is a concern and CO2 will become an important alternative to biomass for fossil-free polymers.