**5. Plastics and the circular economy**

The global recognition of a fundamental shift in the design, use, and reuse of plastics is implicit to his new economic order. A CE advances a closed-loop system where materials are kept in the product lifecycle and not disposed of to reduce raw material usage and energy demand. The concept of a circular economy was proposed over 30 years ago as the impacts of the traditional open-ended economy with no recycling and the environment was being treated as a waste sink became obvious. Previously, the policies of many governments have been focused on encouraging pollution reduction, promoting closed-loop waste management by increasing recycling and dematerialization. For example, the Pollution Prevention Act of 1990 in the United States encouraged reducing pollution at the source and the three Rstrategies: reduce, reuse, and recycle. Similarly, the 1996 German law Closed Substance Cycle and Waste Management and the 2002 Japanese law for Establishing A Recycling-based society [12–14].

A shift to a CE could create a disruptive change that is restorative and regenerative by intention, including green by design that generates no waste, keeps products and materials in use, and regenerates natural systems (**Figure 3**). The plastic industry CE deals with environmental impacts, resource scarcity, disruption in traditional end-of-life management options, and simultaneous economic benefits. To create a successful CE of plastics, various approaches should be followed,

**Figure 3.** *Schematic of the circular economy of plastic.*

including eliminating problematic plastics, innovating to ensure that unused plastics are reusable and recyclable, and circulating the plastic in the economy. The complete lifecycle of plastics should be analyzed with reference to their ability to circulate back for reuse to the economic system to achieve the maximum value.

One of the cornerstones of CE is the creation of an effective after-use plastics economy requiring more material value and higher resource productivity. This requires designing products for recyclability, including designing nonrecyclable packages to become recyclable, which can be achieved by using a mono-material design modifying protective coatings, introducing components that will increase compatibility with processing, developing film-orientation technology, and simplifying the product design for ease of recycling. Many of the most common plastics are recycled at meager rates in the United States. When recycled, they are often recycled into lower-value products due to the degradation of polymer properties resulting from mechanical recycling. To support increased recycling, new plastic recycling protocols should ensure that the monomer stream generated after depolymerization is free from contaminants and colors, a common problem with the chemical recycling of plastics.
