Biodegradable Plastics

Plastics have become an important aspect of almost every part of our lives; from the moment we wake up and brush our teeth with a plastic toothbrush, to the automobiles we drive to work. No material on earth has been so highly valued for its usefulness, yet so maligned, as plastic. Plastics are so clearly useful that it is foolish not to afford them major respect. They are often not only less expensive than alternative materials, but their properties often make them better! 

Market forces such as low cost and convenience have encouraged the use of plastics in the last couple of decades. Most of the commercially available plastics are conventional petroleum-derived plastics such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polystyrene (PS).  Conventional petroleum-derived plastics have remarkable properties for a vast range of applications, but they post serious environmental challenges because of their persistent nature and problems related to disposability. For example, the incineration of recyclable plastics produces carbon dioxide and other harmful gases such as carbon monoxide and bi-products; all which are harmful to the environment. Limited petroleum resources and rising crude petroleum prices are also affecting the economics of the plastic and packaging industry.

With depleting petroleum based resources, the rising global concern for climate change, and plastic waste escalating to over a 200 million tons in North America, it is without doubt that research is needed for discovering alternative types of materials that are better for the environment.[i] In fact, of the 200 million tons of waste generated, 26 million tons are manufactured in North America. Surprisingly, the United States Environmental Protection Agency reported in 2003 that only 5.8 percent (%) of those 26 million tons of plastic waste were actually being recycled.[ii] Overall, the plastic industry is one of the most successful industries in history, and has grown to $2.5 trillion a year in roughly 50 years[iii], so even a 1% infiltration into this market would mean substantial profit, and more importantly, a reduction in the amount of petroleum derived plastics being produced.

A majority of today’s plastic that is produced is used for packaging. For instance, in the United States, approximately 32 percent of the plastic produced each year (over 20 billion pounds) is devoted specifically to packaging, representing its largest use by far, as evident in Figure 1.[iv] Furthermore, of the 27 billion pounds of polymers processed into flexible packaging in 2004, the United States and Canada had a 24.2% share of that market. A majority of these plastics being petroleum based polymers whose future either resides in landfills or facilities where they are to be incinerated into toxic gas. In fact, last year, of the 28.9 million tons of plastic packaging generated, only 5.7% was recycled or reused in some way, and 94.3% was sent to a landfill and discarded or combusted into the environment.[v]

If food companies and citizens do not take responsibility and an interest in this matter soon, the amount of waste generated is going to reach an incredible high, and result in unforgivable damage to the ecosystem. Datamonitor.com, a world-leading provider of premium global business information, is already predicting market production for containers and packaging to reach to 8.7 million tonnes by the end of 2013, representing a current annual growth rate (CAGR) of 1.6% for the 2008-2013 period.  A majority of this waste will come from plastics, as demonstrated in the Figure 2. This further emphasizes the need for biodegradable polymer materials for packaging food.  

Figure 1: Uses of Plastics Produced in the United States. [vi] 
Redrawn after reference: American Plastic Council. (2008) Percentage Distribution of Thermoplastic Resin Sales and Captive use by Major Market-2008. Available: www.americanplasticscouncil.org. Online: April, 2010.

Figure 2: Containers and Packaging Market Segmentation I: % Share, by Value, 2008.

[vii] Redrawn after reference: Euromonitor International, (July 2009). Food Packaging-Canada. 

References

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[i] Naturalvina (2010) Biocompostable Products Quoting Society of Petroleum Engineers. Our World Our, Environment. Available: http://www.zippaq.com/environment/thinkgreen/index.html. Online: April 24th, 2010.

[ii] Mo, X., Sun, J. (2001) Thermal and Mechanical Properties of Plastics Molded from Urea-Modified Soy Protein Isolates. Journal of the American Oil Chemists’ Society, 78(8), 867-872.

[iii] Finlayson, L. (2010) Cereplast, Inc. Press Release: Cereplast Introduces 11 New Grades of Bioplastic Resins for Wide Range of Plastics Applications. Beckerman Public Relations. Available: http://investor.cereplast.com/releasedetail.cfm?ReleaseID=478316. Online: August 25^th, 2010.

[iv] Stevens, E.S. (2003) Green Plastics: An Introduction to the New Science of Biodegradable Plastics. Library of Congress Cataloging-in-Publication Data. Princeton University Press United States of America.

[v] Ruixiang, Z., Torley, P., Halley, P. (2008) Emerging biodegradable materials: starch- and protein-based bio-nanocomposites. Journal of Material Science, 43, 3058-3071.

[vi] American Plastic Council. (2004) Percentage Distribution of Resin Sales and Captive use by Major Market-2004. Available: www.americanplasticscouncil.org. Online: April, 2010.

[vii] Euromonitor International, (July 2009). Food Packaging- Canada. Available: www.euromonitorinternational.com. Accessed via: McGill University’s VPN connection, Management Resources.

© new wave ideas -Sara Bonham