STEM

Opinion: The life cycle of plastic is complex

By ETHAN SIBBET

Plastic: it surrounds us and is deeply involved in nearly everything we do, yet the layman knows next to nothing about it. As the superstition goes, you are never further than three feet from a spider. Well, you are never further than three feet from plastic. There is no escape.

There are, of course, your clothes, which are partially plastic due to the tags, and if they don’t have tags they likely have plastic residue or protection mixed with the cloth. In addition, your shoes are either plastic or rubber, which is a type of plastic. According to “Molecules” by Theodore Gray, if by chance your clothes are not made from plastic, you still have your phone, whose case and certain electronic parts, such as the battery, are plastic.  

So, where does this ubiquitous plastic come from?

I asked people at Citrus Valley where they thought plastic came from. Their answers were fascinating; many had no idea or guessed wildly. It was surprising how many people answered the ocean (which is actually correct from several perspectives). Another insightful but not-exactly-correct answer was consumerism. Fortunately, I did manage to provoke some of those who had no idea where plastic comes from to think about the question. Hopefully, they will be more careful with their plastic use in the future.

Plastic is refined oil. Fossil fuels of all types are composed of carbon polymers, which have very different properties based on their length (length referring to the number of carbon monomers in a chain). Shorter chains vaporize at lower temperatures and are less viscous.

At a molecular level, the hydrogen atoms on each chain “catch” each other, keeping the substance more stable; as the length of the polymers increases this effect becomes more and more pronounced. Above 20 or 30 carbon monomers, the substance becomes so viscous it is basically solid.

The process of refining the oil consists of separating the different chain lengths by their heat of vaporization, which is the temperature at which they vaporize. The plastic used in plastic bottles or your phone case is between several hundred and several thousand carbon units long.

In other words, a dinosaur died and slowly decayed until it mixed with the decayed remnants of ferns. Then it went underground and plate tectonics made its gasoline. Afterward, people dug up the gasoline and made it plastic.

Plastic is then used by you for an infinitesimally small moment of its life. You put trash in it, package food in it or even put it in a car, printer or phone. Then in a flash, it is trash again.

Where does plastic go afterward?

Once you throw your plastic in the trash, it is picked up and taken to a landfill or China, where it is either burned, forgotten, buried or sorted by some poor Chinese chemical worker. According to “High Tech Trash,” there is only a small portion that stays in the US and is recycled there. However, China just banned a portion of the plastic the US and Europe send to it. How this plastic will be processed is yet to be seen.

The burned plastics turn into toxic gases, the remnants of which float out and eventually cool, falling to earth and waiting to decompose.

If the plastic is forgotten or buried, it remains for hundreds of years until microbes eventually manage to decompose it. In the meantime above ground, stadiums are built, grasses grow and children play.

Once it is recycled and sorted, the toxins the Chinese workers use to sort the plastic cause horrible cancers and diseases. According to “High Tech Trash” by Elizabeth Grossman, the part that is recycled in the US, though, is recycled in industrial plants without danger to human life.

Eventually, the recycled plastic leaves the system, either as trash or when humans go extinct. At that point, all the plastic continues decomposing and eventually disappears after anywhere between a hundred and thousands of years.

Categories: STEM

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