Polyethylene Terephthalate
A look into sustainable polymers
The plastic crisis
It is estimated that up until 2017, 8,300 million metric tons of virgin plastic has been produced.1 Of the 35.860 million tons of plastic materials generated in municipal solid waste in 2018, only 3.09 million tons was recycled and 26.97 million tons was discarded in landfills.2 The slow degradation rates of plastics in landfills, over 5,000 years for some plastics, has allowed for the rapid accumulation of plastics in our environment. If low rates of recycling and plastic degradation persist, 12,000 million metric tons of plastic waste will have accumulated in landfills or the natural environment by 2050.1
It is estimated that 8 million tons of plastic waste enters the oceans every year harming the wildlife in marine ecosystems.4 Animals are trapped in plastic and ingestion of plastic particles causes health problems that often result in death.5 Although the amount of fossil fuels used as the main carbon source for plastic production is small, it is not insignificant.5 When plastic is degraded or industrially converted into carbon dioxide, the emission of greenhouse gases is non-negligible.5
In order to address the plastic crisis, scientists are looking at alternative methods to form and dispose of plastics. Polymers must be derived from natural and renewable sources in a cost and material-efficient manner and extend beyond having a single-use.
Plastic lifecycle
Commodity polymers
References:
[1] Geyer, R., Jambeck, J. R., & Law, K. L. (2017a). Production, use, and fate of all plastics ever made. Science Advances, 3(7), e1700782.
[2] US EPA, O. (2017, September 12). Plastics: Material-specific data [Collections and Lists], plastics-material-specific-data.
[3] Schneiderman, D. K., & Hillmyer, M. A. (2017). 50th anniversary perspective: There is a great future in sustainable polymers. Macromolecules, 50(10), 3733–3749.
[4] Hillmyer, M. A. (2017). The promise of plastics from plants. Science, 358(6365), 868–870.
[5] Hottle, T. A., Bilec, M. M., & Landis, A. E. (2013). Sustainability assessments of bio-based polymers. Polymer Degradation and Stability, 98(9), 1898–1907.