Sciencemadness Discussion Board

How to make organic, epoxy-like material?

dominique4 - 29-7-2015 at 00:06

Hi,

I'm an artist and work on an installation piece. Regarding to the concept of the exhibition, I use only plant based materials. I would like to make a transparent, epoxy-like stuff, which I can pour into a cast and becomes solid when dries out.
It also has to be somewhat durable. Could you recommend any materials?

Thank you for your help in advance!

Dominique

Ozone - 29-7-2015 at 04:39

Well, styrene would polymerize (with an added initiator) in a mold to give a hard, clear item. It was originally isolated from storax, a plant resin:

https://en.wikipedia.org/wiki/Styrax_balsam

Extracting the needed quantity would be a messy trial, so perhaps rolling back a bit, look at some plant resin exudates known to cast amber and the like. Perhaps the curing of some of these could be accelerated by using an appropriate initiating compound?

O3

Sulaiman - 29-7-2015 at 04:41

agar-agar in water sets clear
but is nowhere near as strong as epoxy resin.
a concentrated solution will be almost solid on setting.
Molten sugar is another possibility?

[Edited on 29-7-2015 by Sulaiman]

Ozone - 29-7-2015 at 14:33

Sugars don't really melt. They lose water and decompose (via polymerization of intermediate HMF, etc. to yield caramel, then carbon).

O3

aga - 29-7-2015 at 15:08

agar-agar is your best bet, as Sulaiman said.

It does not set solid like rubber, or a rock : more like jelly.

It is however easy to get and is an extract from seaweed (i.e. from a natural source).

'Natural' is Highly subjective.
We (humans) are a natural product of this planet, therefore what we make is also natural.
However, i digress ...

To solidify it more, and confrm to your criteria, stuff the mould full of stringy organic material like coconut fibre, dried seaweed, hemp fibres, willow fibres or whatever you find that is stringy, then pour in your hot agar-agar.

Experiment with trying to dry then powder your organic stringy stuff and add it as a powder when making the agar solution.

Might make the result more 'solid'.

crazyboy - 29-7-2015 at 15:10

How much do you need, and can you be more specific about the specifications? (How critical is transparency, strength, cost?)

I don't think you'll have much luck finding anything clear, and as strong as epoxy derived from plants. Early plastics were poor for a reason. Here are some possibles.

Carnauba wax, rosin or other natural resins, shellac, or sugar.

Shellac is insect derived, carnauba wax won't be transparent, resins may or may not be transparent. I think sugars are your best bet, they can be easily extracted from sugar cane or sugar beets and people make very intricate sugar sculptures regularly.

If you want something more exotic/interesting I think a resin such as rosin would be better. High grade rosin is transparent and should be castable.

Bert - 29-7-2015 at 18:50

How to make an organic, epoxy composite like material?

Plant a tree!

Morkva - 30-7-2015 at 13:21

Organic, eh. Organic chemistry! Ha, ha.

Sugar can, indeed, be cast, they use it for prop windows in movies where it is impractical to injure someone jumping through real glass. Also, candymakers are familiar. There are various sugars you could cast and 'sugar alcohols' like sorbitol, erythritol etc: probably a combination can be looked up which has a preferable melting point.

If only you could carry out transformations chemical on plant based material, using only non-mineral/non-air based chemicals... lets see here. You might polymerize some alkene substances. The quickest search for "polymerization of pinene" gives some results. Apparently it can be done.

Green Polymerization Methods: Renewable Starting Materials, Catalysis and ...
edited by Robert T. Mathers, Michael A. R.
https://books.google.com/books?id=KwBwC9QaTXAC&pg=SA5-PA...

A Study of the Polymerization of α- and β-Pinene with Friedel—Crafts Type Catalysts
http://pubs.acs.org/doi/abs/10.1021/ja01159a044

These are the chief constituents of turpentine, of which, the smell I love. I wonder if there's a plant based catalyst/initiator. Acetic acid? There are other unsaturated compunds in plants like in the essential oils of tarragon, cinnamon, and garlic or onion (why would diallyl disulfide fail to polymerize?) but much too expensive.

One of the first resins used and for waterproofing raincoats - if I'm not too mistaken, was derived from glycerol and phthalic acid, a kind of polyester. Substituting citric acid for that should make some kind of polymer, but which would require lots of heating to boil the water away.

From corn cobs and some others, one obtains by distillation with hydrochloric acid "furfural" which does polymerize. That's an idea.

Cellulose is the... characteristic? quintessential? plant matreial. Cellulose can be dissolved and percipitated to a hard mass, most easily and historically with copper hydroxide (it is easy to rust copper for that) and ammonia - "schweitzer's reagent", but there are the cellusolves, and other types of solvents you might find interesting to use in your other works, being an artist. Or to ruin people's clothes.

Then there's linseed oil, which you, as an artist are already aware of. Still, it is delicious with honey on toast.

[Edited on 30-7-2015 by Morkva]

aga - 30-7-2015 at 13:51

Looks like dominique4 got bored after the word 'polymer' was mentioned, and has probably vowed to remain true to roots and make everything from elephant dung as an artistic Statement.

Good on 'em, and best of luck with the installation.

pneumatician - 2-8-2015 at 17:08

Quote: Originally posted by dominique4  
Hi,

I'm an artist and work on an installation piece. Regarding to the concept of the exhibition, I use only plant based materials. I would like to make a transparent, epoxy-like stuff, which I can pour into a cast and becomes solid when dries out.
It also has to be somewhat durable. Could you recommend any materials?

Thank you for your help in advance!

Dominique


wow! I are in the teorize to go at work with a substance nobody say! AMBER!!! :)

so if you want 1, 2, 3 liters of amber in liquid from light yellow to crystall clear, you can put someting "inside"... the end process of course is amber hardened again. So if you have a pocket full of banknotes contact me! :)
now I have a process for only to soft amber, so I think you can put someting inside, is like working with soft clay, after some minutes the amber is hard-natural again, but this proces involve no purification so the amber have the color-impurities as before.

Ozone - 3-8-2015 at 09:42

Not exactly, "look at some plant resin exudates known to cast amber and the like."

Anyhow, what about nitrocellulose?

Citric acid:glycerol does indeed polymerize, but it is highly cross-linked (conversion <0.25%) and requires a slow cure to solidify--and the increasing viscosity during the cure creates steam bubbles that can limit the thickness a cast item.

Furfural does polymerize (acid and heat)--but, it yields an opaque brown/black solid.

O3



kecskesajt - 6-8-2015 at 11:30

Sorbitol is another option.Or other sugar alcohols.But only if you dont care of water absorbation.If you have some clear lacquer,melt and mold it and then dip it in there.

Ozone - 6-8-2015 at 12:46

Mannitol isn't hygroscopic like sorbitol.