
Recycling of plastics enabled by dynamic covalent diketoenamine bonds (2018) [pdf] - inflatableDodo
http://ipo.lbl.gov/wp-content/uploads/sites/8/2018/03/Helms-Closed-Loop-Recycling-Nature-Materials.pdf
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apo
The idea is to construct plastics using reversible polymerization "click"
reactions. Polymerize the monomers under mild conditions. Recover them again
through acid degradation. Build entirely new kinds polymers (if you want) with
the monomers you recover.

Notable features include:

1\. synthesis involves ball-milling the starting materials, which eliminates
the need for solvent

2\. decomposition in sulfuric acid (0.5-5 M) gives one component of the pair
of monomers (triketone) cleanly, but amine recovery is less clear.
Quantitative recovery wasn't clear from my reading.

3\. the mechanical properties of the small set of possible polymers produced
from this system appear consistent with at least certain kinds of industrial
use.

4\. the chemistry lends itself to the production of a wide range of different
polymer structures, but the sensitivity of the key bond forming/breaking step
to starting monomer modification remains to be shown.

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Iv
Let me do a tl;dr because that's an important subject that could cange plastic
from environmentally problematic material to a highly renewable one.

Recycling plastic is hard because we have different types of plastic for
different uses. If you mix them in a trash, it is hard to take them apart and
recycling them together leads to very poor materials.

Nowadays, there is active research in making a more intensive recycling that
retransforms plastics into their precursors, which are basically the same even
for different types of plastic, so this is a process that do not require to
sort plastics by type.

Only scanning through the article, it looks like this is a solution to
separate these precursors from the remaining impurities (coatings, ink,
colorant) and get pure monomers. That's an important step in the process.

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softwarelimits
Because that institution also seems to be heavily engaged in the area of
"Intellectual Property" I would like to mention:

one big reason for the problems with plastic recycling is the fact that
producing companies do want to "protect" their "intellectual property" and do
not provide a list of ingredients.

This is an area where IP does have a very big impact in the global
contamination process.

~~~
userbinator
_one big reason for the problems with plastic recycling is the fact that
producing companies do want to "protect" their "intellectual property" and do
not provide a list of ingredients._

That has to do with the additives, not the base --- and you are correct that
separating these otherwise contaminants from the base material is important
for recycling. On the other hand, everyone knows what the base materials for
Teflon and polyethylene are, for example.

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softwarelimits
Using the big searchbox it is not possible to find this document, you need to
use the small searchbox on top.

Then you can find this post that seems to be related.

[https://foundry.lbl.gov/2019/06/05/new-polymers-close-the-
lo...](https://foundry.lbl.gov/2019/06/05/new-polymers-close-the-loop-in-
plastics-recycling/)

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mrnobody_67
Bunch of interesting stuff being done to turn plastic into diesel:
[https://www.cbc.ca/news/canada/nova-scotia/sustane-
technolog...](https://www.cbc.ca/news/canada/nova-scotia/sustane-technologies-
plastic-fuel-diesel-environment-1.4735539)

