What if we could make plastics from less harsh
products? This means we get rid of them much easier and in a much safer way.
Most bioplastics are made from natural materials like corn starch. Some
bioplastics look identical to traditional petrochemical plastics. The main
ingredient in bioplastics is Polylactide acid (PLA), which looks and behaves
like polypropylene and polyethylene, widely used for the production of food
containers.
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| Turning shrimp into plastic: Harvard's Wyss Institute comes up with fully degradable bioplastic |
Producing PLA, according to NatureWorks, saves
two thirds the energy you need to produce traditional plastics. However, a
problem remains, even with the advent of bioplastics. Those currently in use do
not fully degrade in the environment. Also, their use is limited to packaging
material or producing containers for food and drink.
Researchers at Harvard’s Wyss Institute for
Biologically Inspired Engineering have now introduced a new bioplastic,
isolated from shrimp cells. It is made from chitosan, a variety of chitin – the
second most abundant organic material on Earth. The main ingredient in the hard
crustacean shells is the tough polysaccharide, chitin. The Wyss Institute makes
its ‘shrilk’ from chitin from shrimp shells most which would otherwise be
discarded or used in fertilizer or makeup, and a fibroin protein from silk (Gazette, 2014) .
Wyss Director, Donald E. Ingber in March 2014
said, ‘There is an urgent need in many industries for sustainable materials
that can be mass produced. Our scalable manufacturing method shows that
chitosan, which is readily available and inexpensive, can serve as a viable
bioplastic that could potentially be used instead of conventional plastics for
numerous industrial applications.’ This environmentally friendly plastic could
also serve in the manufacture of diapers, trash bags, and for packaging.
Even more exciting news, shrilk breaks down in
just a few weeks, when discarded, it even releases rich nutrients that assist
plant growth. According to researchers at Columbia University, the United
States alone generates about 34 million tons of plastic every year, with less
than 7% being recovered for recycling. According to these researchers, plastics
buried in landfills will take 1,000 years to degrade.
Drawbacks to Bioplastic
·
Some bioplastics like PLA,
are made from genetically modified corn, a variety of crops considered by most
environmentalists to be implicitly denigratory to the environment.
·
Bioplastics are made from
plants like corn, land for agriculture is readily forgone for the ‘cultivation
of plastic’, and possibly causing a significant increase in food prices – the
poorest are hit hardest!
·
Bioplastics cannot be easily
recycled. PLA looks similar to PET (Polyethylene Terephthalate) but when mixed
in a recycler, the mixture becomes impossible to recycle. The increasing use of
PLA may be a threat to the recycling of plastic.
Gazette, H. (2014, May 5). Promising Solution to plastic
pollution. Retrieved May 24, 2015, from Havard Gazette:
http://news.harvard.edu/gazette/story/2014/05/promising-solution-to-plastic-pollution/
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