Green Chemistry and beverage bottles What does green chemistry have to do with the bottles that a lot of us drink from every day? © 2017 www.beyondbenign.org

The job of green chemist Problem solver The job of a green chemist is to solve problems using the 12 principles.

The problem with PET bottles Made from a non-renewable resource Do not biodegrade Do not recycle on a closed-loop system

Lets start at the beginning In the process of making the bottle, two dimers are zipped together to form a polymer, like the chain you made at the beginning of the lesson DMT To form the PET polymer, two dimers, DMT and Ethylene Glycol are zipped together rather like your paper chain. Think about taking this chain apart and how careful you would need to be and how the paper would probably rip and never look the same as it did before. That is because the paper and been bonded with a strong material and has made something else. Ethylene Glycol

This zipping produces a polymer (or many monomers) to form the PET molecule To make this revolutionary molecule

Lifecycle of a PET beverage bottle So what is the lifecycle of that bottle – The petroleum is mined, refined and made into a polymer and a bottle. Then it is used and discarded…then what? It either goes into a landfill where it will be for about a 100,000 years or…

Recycling can make this.. Chemists have already figured out a way to make PET bottles, Lumber substitutes (like those green plastic park benches) ,Flower pots, Pipe , Toys, pails and drums Traffic barrier cones,Trash cans into carpets, insulation in clothing and guard rails for roads. So chemists have successfully figured out how to recycle PET in an open-loop system but how do we make it closed loop But we still use PET bottles so we are still using petroleum

What if the Lifecycle of a PET beverage bottle looked like this… The bottle that has already been made from petroleum is used, discarded and then through the brilliance of green chemistry, is made back into the very same bottle

In 1996 the DuPont Company won a presidential Green Chemistry Award for Petretec -or the unzipping of the polymers in PET The petretec process is the unzipping of the polymer back to two dimers which are perfectly in tact so that they can once again be made back onto PETE.

Petretec chemical reaction http://academic.scranton.edu/faculty/CANNM1/industrialchemistry/industrialchemistrymodule.html The scrap PET is dissolved in DMT at a temperature of above 220 degrees celcius and then reacted with methanol. The PET is then Transesterified which means that one ester group type was converted to another ester group type to produce DMT and ethylene glycol again which can be made to make a new PET bottle The DuPont Company at their plant in North Carolina uses this process to recover 100 million lbs of PET annually

Has the problem been solved? Made from a non-renewable resource The non-renewable resource is now renewable Do not biodegrade This would be solved if we could get everyone to a Petretec processing plant Do not recycle on a closed-loop system Petretec is a closed-loop recycling system Green chemistry provides a framework for scientists to be able to solve problems for society