
Scientists make plastic from a sugar and carbon dioxide - phr4ts
http://www.bath.ac.uk/research/news/2017/06/12/scientists-make-plastic-from-sugar-and-carbon-dioxide
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derefr
Fun fact: cellulose (in wood) and chitin (in insect exoskeletons, fish scales,
fungus cell-walls, etc.) are _also_ polymers of glucose-derived sugars. Both
are biodegradable, although _humans_ can only digest the latter of the two.

Other fun fact: before the invention of entirely-synthetic plastics, we had
_phenolic sheets_ : layers of plain cellulose _laminated together_ ,
originally using natural resin (tree sap), then later using synthetic resins,
like Bakelite. These didn't have all the properties of synthetic plastics—you
couldn't bend them, for example—but you could form them into shapes and
introduce pigments, etc., while manufacturing. The earliest Printed Circuit
Boards were Bakelite phenolic boards. (And even today, PCB insulator material
is effectively a "synthetic phenolic board": it's _fibre-reinforced plastic_ ,
which uses plastic itself in place of resin—and various synthetic fibres in
place of cellulose—to achieve the same properties phenolic sheets have.)

~~~
workerIbe
Another feature of Bakelite is that after 60 years or so it tends to smell
strongly, closely mimicking the smell of vomit. Hopefully any new formulations
fare better.

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fokinsean
> This new type of polycarbonate can be biodegraded back into carbon dioxide
> and sugar using enzymes from soil bacteria

This sounds amazing, but reading about various awesome breakthroughs has made
me a bit cynical since there always is some sort of catch.

Does anyone know any limitations to this method which would make it difficult
to scale?

~~~
Analemma_
If there are any, they'd probably be discussed in the actual papers and not
here. I don't know if the UK is better, but at least in the US, university
press releases about this or that research paper are usually garbage.

Does anyone have access to the actual papers?

    
    
        Georgina L. Gregory, Gabriele Kociok-Köhn and Antoine Buchard 
        “Polymers from sugars and CO2: ring-opening polymerisation and copolymerisation of cyclic carbonates derived from 2-deoxy-D-ribose” 
        DOI: 10.1039/C7PY00236J Polymer Chemistry, 2017, 8, 2093-2104
    
        Georgina L. Gregory, Elizabeth M. Hierons, Gabriele Kociok-Köhn, Ram I. Sharma and Antoine Buchard 
        “CO2-Driven stereochemical inversion of sugars to create thymidine-based polycarbonates by ring-opening polymerisation” 
        DOI: 10.1039/C7PY00118E Polymer Chemistry, 2017, 8, 1714-1721
    
        Georgina L. Gregory, Liliana M. Jenisch, Bethan Charles, Gabriele Kociok-Köhn, and Antoine Buchard 
        “Polymers from Sugars and CO2: Synthesis and Polymerization of a d-Mannose-Based Cyclic Carbonate” 
        DOI: 10.1021/acs.macromol.6b01492 Macromolecules, 2016, 49, 7165-7169

~~~
asdfghj123
[https://sci-hub.io/10.1039/C7PY00236J](https://sci-hub.io/10.1039/C7PY00236J)
[https://sci-hub.io/10.1039/C7PY00118E](https://sci-hub.io/10.1039/C7PY00118E)
[https://sci-hub.io/10.1021/acs.macromol.6b01492](https://sci-
hub.io/10.1021/acs.macromol.6b01492)

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mchannon
The title of the article's pretty misleading. "sugar" means to most people
either sucrose or glucose. Fructose, lactose, etc. could also qualify.

No, this uses a very obscure and expensive chemical called thymidine (most
cost-effectively harvested from herring sperm, and primary precursor for anti-
AIDS drug AZT). It may be "a sugar", but this article's playing fast and
loose, akin to calling any pharmaceutical that ends with citrate or chloride
"salt".

~~~
mrob
It also calls polycarbonate "scratch-resistant" when anybody who's worked with
it knows it isn't. "Scratch-resistant coatings for phones, CDs and DVDs",
really? CDs and DVDs are made of polycarbonate and they scratch easily.

~~~
Retric
Resistant is always a though word. The important, but hidden measurements are
cost to produce, etc but relative to most other cheap, though, and clear
materials...

CD's are actually very scratch resistant even though they often get lot's of
small scratches.

~~~
jdmichal
> CD's are actually very scratch resistant even though they often get lot's of
> small scratches.

This is a bit of an oxymoronic sentence. How can something be both scratch
resistant, while accumulating a large number of scratches?

The scratches a CD accumulates won't typically affect the ability to read from
them, but that's due to the focal length of the reader, not the material.

[https://en.wikipedia.org/wiki/Compact_disc#Integrity](https://en.wikipedia.org/wiki/Compact_disc#Integrity)

~~~
Retric
Resistance _is not_ immunity.

Bullet proof glass for example gets damaged by bullets. The trade off is
always in how much damage and how quickly. CD's will easily survive with even
moderate levels of care.

What people forget is the covering is really designed to protect the _data
layer_ not the surface. And in that context the clear plastic is actually
better protection than the backside.

~~~
jdmichal
> What people forget is the covering is really designed to protect the data
> layer not the surface.

Right. But that this started explicitly about calling the _polycarbonate_ \--
that clear layer -- as scratch resistant. And this is just flat out wrong:

"Polycarbonate is a durable material. Although it has high impact-resistance,
it has low scratch-resistance."

[https://en.wikipedia.org/wiki/Polycarbonate#Properties_and_p...](https://en.wikipedia.org/wiki/Polycarbonate#Properties_and_processing)

I agree that it serves its purpose of protecting the data layer of the CD. But
again, CDs and their readers were designed in a way that typical surface
scratches and other imperfections would not inhibit reading. And so
polycarbonate was an acceptable choice. The same approach applies to eye glass
lenses; a scratch on a lens is typically not in focus and therefore has little
to no effect on vision.

So, TL;DR: Polycarbonate the material is not scratch resistant. CDs are
scratch resistant, but that is due to their optical design and _in spite of_
the polycarbonate.

~~~
Retric
I don't directly disagree with what your saying, my point is there is more
than one type of scratch resistance. Because not all scratches are created
equal. If you look at say :[https://omnexus.specialchem.com/polymer-
properties/propertie...](https://omnexus.specialchem.com/polymer-
properties/properties/hardness-shore-d)

You find it's good relative to other plastics at preventing penetration which
is also why it's good at preventing _deep_ scratches. So, yes if you want a
crystal clear optical element then it's not scratch resistant and look for
something high on the Mos scale. But, if you want a coating that protects from
deeper scratches it's quite good. In that context it's good material to
protect CD's from scratches that matter.

Which again is why I find the word resistance tricky because it's always
resistant in some context.

~~~
jdmichal
Ah, I understand your point now. Thanks for clarifying for me.

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collyw
I read the headline and though "just what we need more plastic". I was
pleasantly surprised to see that its biodegradable

~~~
wuschel
The question is, under what degradation conditions (time, bacteria, etc), and
what other threat vector does the material bring to animal life.

~~~
collyw
True, but biodegradable is still better than not.

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jwdunne
Well no. Plastic biogrades at a snail's pace. Timescales differ on type of
plastic. Plastic bags apparently​ take 20 years to biodegrade, for instance.
PVC pipes are used in plumbing because biodegradation is extremely slow - not
that it doesn't ever happen.

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collyw
I wasn't aware that plastic bags / pipes biodegraded at all, hence my
position.

~~~
jdmichal
I think plastics are one of those things where, dumped into a random place,
they probably won't be biodegraded. However, for any given plastic, there is
probably some organism in existence which will eat it under some or all
conditions. So the usage of "biodegradable" maybe depends on which viewpoint
you are interested in.

For example, here's the wiki on polyethylene, which seems like the typical
plastic for "plastic bags" from a store:

[https://en.wikipedia.org/wiki/Polyethylene#Biodegrading_plas...](https://en.wikipedia.org/wiki/Polyethylene#Biodegrading_plastics)

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ValleyOfTheMtns
Sounds like this could also be really useful for future manufacturing
industries on the surface of Mars or in the atmosphere of Venus. Polycarbonate
also seems to have some resistance to sulfuric acid, which would be
particularly useful in the Venusian atmosphere.

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2_listerine_pls
After extracting the sugar, many sugarcane mills burn the biomass (bagasse)
for energy. So, they already have a free supply of CO2.

edit: Never mind, they are talking about another type of sugar.

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yellowapple
Any details available on the processes involved?

