Recycling biodegradable polymers

Biodegradable polymers are macromolecules mainly derived from renewable sources, which can be enzymatically or hydrolytically degraded into low molecular parts. These parts can be reabsorbed by microorganisms, which ideally convert them to CO2 and water heading to an environmentally closed circular flow economy between growing of nutrients, production, utilization, and material recycling (Fig. 1). 

DuPont offers a family of biodegradable polymers based on polyethylene terephthalate (PET) technology known commercially as Biomax. Proprietary monomers are incorporated into the polymer, creating sites that are susceptible to hydrolysis. At elevated temperatures, the large polymer molecules are cleaved by moisture into smaller molecules, which are then consumed by naturally occurring microbes and converted to carbon dioxide, water and biomass. Biomax can be recycled, incinerated or landfilled, but is designed specifically for disposal by composting. 

Pavlath, A. E. Robertson, G. H. (1999). Biodegradable polymers vs. recycling what are the possibilities Critical Reviews in Analytical Chemistry, 29, 231-41. 

Two solutions to address the waste problem created by polymers are recycling existing polymer types to make new materials, and using biodegradable polymers that will decompose in a finite and limited time span. 

Synthetic polymers are arguably the most important materials made by chemists and used in modem society. Chapter 30 Synthetic Polymers expands on the foundations of polymers discussed in earlier Chapters 15 and 22. Of significance is emphasis on the environmental impact of polymer synthesis and use, discussed in sections on Green Polymer Synthesis (30.8), Polymer Recycling and Disposal (Section 30.9A), and Biodegradable Polymers (Section 30.9B). 

The book reviews the properties and industrial applications of polymers and discusses their environmentai benefits compared with traditional materials. It also addresses the issues of polymer durability, recycling processes to aid waste minimization and biodegradable polymers. This text is intended to introduce the non-specialist reader to the benefits and limitations of polymeric materials from an environmental viewpoint, and will prove a useful book for both students and professionals. 

A solution to this problem would be to reduce unnecessary usage of plastics and to recycle used plastic materials. These conservational efforts could be further aided by replacing some pefrochemical-based plastics with biodegradable material possessing similar properties. One such potential candidate is PHA. This biodegradable polymer with thermoplastic properties is an ideal substitute for conventional plastics. 

---