| Popis: |
Plastics are synthetic polymers that are lightweight and exhibit a high tensile strength, durability, and chemical inertness, leading to a host of applications. However, these same properties make their degradation difficult and have resulted in significant accumulation in the environment. Plastic characteristics include hydrophobicity, degree of crystallinity, molecular size of the constituent polymer, etc. Each character plays a crucial role in plastic biodegradability. The low degradation rates and the subsequent effect on ecology is a major environmental concern. Considerable ongoing research is focusing on the biodegradation of plastics and bioplastics by various microorganisms and their constituent enzymes. These biocatalysts are specific to the constituent functional groups, degree of polymerization, etc. The breakdown rates and composition of the final products depend on several factors including physical and chemical pretreatments. Unlike recycling and composting, these studies aim to break down the plastics to monomeric or short-chain polymers that can be reused. The obtention of reusable “end-of-life” monomers or oligomers and re-introduction into the production cycle will help to complete the loop and the use of plastics from a linear to a circular bioeconomy. Such processes will reduce the original resource input with each complete cycle making the process much more sustainable. With this knowledge, the development of new plastics will move toward the products that can be broken down into reusable compounds after its end-use. This chapter will review the degradability potential of plastics and bioplastics to reusable materials that can be adapted by the plastic industry for a cascading circular bioeconomy. |
