Wizards in Rayon Stockings: Some worldbuilding notes on plastics.

How reasonable is it is include plastics in a psuedo-medieval fantasy world without fossil fuels? 

 

A better title might be "Alchemists in Rayon", because of course you can just wave your witchofingers and summon tupperware from the realms of chaos. But even restricting ourselves to low-magic fantasy, for many plastics, it's totally reasonable to throw them in. They'll probably just be rarer and considered high-quality objects instead of throwaway trash.

Clearly, the question on everyone's mind when they see this compilation of public domain witches is
"Where did they get those sweet leggings?"

Skip to the end if you just want a bulleted list of which plastics I thinks a witch might be able to brew in a cauldron. But otherwise, come with me on this scatterbrained journey into the world of organic chemistry.

 

 

What is plastic anyways?

Plastic is a word which simply means that something is easy to shape. When we use the word as a noun, we're usually talking about a specific group of plastic materials made of man-made polymers.

 

"Polymer" means "many-parts". Polymer molecules are long chains of simpler molecules called monomers ("One part"). Polymer materials are strong and flexible for much the same reason that cloth is strong and flexible. The long chains are tough to snap but can bend and slide past each other.

 

Except that's a bit of a cheaty metaphor because the natural fibers used to make fabric are themselves polymers. In fact, there are lots of polymers in nature, and some early modern plastics were developed as replacements to their natural alternatives.

I - Chains of Sugar - some of the most common stuff on the planet.

"Polysaccharide" means "many sugars". These are polymers made by chaining together simple sugars. Although simple sugar monomers taste sweet and are easy to break apart, they become very strong when hooked together. Starch, cellulose, and chitin are all examples of polysaccharides.

 

Chitin is the stuff that bugs use to form their shells. Mushrooms use it too. Humans haven't figured out how to make chitin in bulk, but we discard a bunch of it as food waste, so there's active research into ways to reform the stuff into useful shapes.

Foreground: polymers. Background: polymers.

 

But the real star of the show is cellulose, the most common polymer on earth. It's what makes plants rigid, and it's the part of plants we turn into paper. Ever held a cotton ball? That's basically pure cellulose. Some animals, like cows, have bacteria in their guts to break cellulose back down into sugar to use as food. The human gut can't do that, but we can still need to eat cellulose as dietary fiber (which adds bulk to stool). Wood is mostly cellulose, but mixed with some wonky tangly polymers called lignin to hold the cellulose together.

 

 Cloth from wood!

 

 

Rayon is chemically the same as cellulose, but arranged into much smoother, more regular fibers, which makes it great for use in textiles. Made by treating wood pulp with lye and carbon disulfide (CS2, originally called "liquid sulfur"). The treated cellulose is then dissolved, and extruded through tiny holes into an acid bath. Because of the similarity between the extruder and a spider's spinnerets, rayon is sometimes called artificial silk.

Cellophane is made the same way as rayon, but a narrow slit is used instead of a spinneret. The name is a combination of "diaphanous" (thin enough to be transparent) and "cellulose". It's used in food packaging, and other situations where clear, slightly breathable wrapping is desired.

Because both rayon and cellophane are essentially just smooth, thin bits of cellulose, both materials are biodegradable. However, the word "cellophane" is often used to refer to other sorts of plastic film which aren't biodegradable. For example, when I search for "cellophane" on Amazon, the first result (and best seller) is actually made of polypropylene. -_-

 

Practical Wizard Fashion
(And very thematic for a Spider Wizard.)

 

Liquid sulfur wasn't discovered until the 1700s, but it can made just be heating sulfur and wet charcoal, so I'm going to include both of these in the bucket of things a wizard could concoct in their tower without modern industrial processes.

 

Oh yeah, and you can also make cellulose go kablooey.

Here's where the alchemy comes in.

 

Soak cotton fibers in a mixture of aqua fortis and oil of vitriol. Hang the cotton to dry, and you will find that it retains its appearance, but has been imbued with all the strength and fury of the mixture. (Don't actually do this though.)

 

Yep, it's really that easy to turn good old cellulose into nitrocellulose (aka gun cotton, flash paper, and many other names). It makes a big boom. The ingredients and processes were all available and known to a medieval alchemist, but the actual recipe wasn't discovered until the 1840s. (One apocryphal story goes that a chemist wiped up an acid spill with a cotton apron, and the apron later spontaneously exploded after being hung up to dry.)

Another nice property of the stuff is that it can be easily dissolved and then allowed to dry into a shiny hard plastic coating. This is used for all sorts of stuff, from playing cards to nail polish. Yes, the stuff that makes your nails shiny happens to be an explosive.

 

And that explosive became the first modern plastic.

Celluloid is a mixture of nitrocellulose with camphor, which is a stinky wax harvested from the camphor laurel. The camphor makes the nitrocellulose stronger and easier to work with. Celluloid is a thermoplastic, which means that it can be heated to become soft, dissolved or molded into shape (injection molded even), and then cooled back down to become hard. 

 

Celluloid's first application was as a replacement for the ivory (elephant tooth, itself a polymer composite) previously used to make billiard balls, and soon became widely popular as a replacement for horn and ivory in all sorts of applications. Celluloid film was also the first flexible material which could hold photographs. This flexibility allowed many small photographs to be stored on a long coiled strip of film, and led to the rise of moving pictures as an art form.

 

Probably won't explode.

Oh, but do remember that this stuff is basically gunpowder. The camphor makes the nitrocellulose significantly less explosive, but it's still a tiny wee bit explosive. Early celluloid billiard balls would sometimes explode on impact, and the tendency for decaying film to spontaneously burst into flame is a substantial problem for the presevation of early video footage. If you have any regulation ping-pong balls from before 2014, make sure to keep them away from open flame.

 

 

A safer alternative

The film industry eventually switched from nitrocellulose to cellulose acetate for making film stock, calling the new stuff "safety film". Safety film isn't immune to decay, but instead of turning into high-grade explosives in the process - as celluloid film does - decaying safety film just turns into vinegar.

 

The process for making this stuff starts by soaking cellulose in a mixture of sulfuric acid, acetic acid (vinegar), and acetic anhydride. It's this last one that poses a problem for our hypothetical alchemist. Acetic anhydride can be made from acetic acid, but the process involves some weird catalyst that I'm not sure would be easy to find in ye olde times.

 

 

 

 

 

II - Formaldehyde - Not just for preserving lizards in a jar!

These next group of plastics are made using some stuff called formaldehyde. Formaldehyde is made from wood alcohol (methanol), and is used as a medical preservative. Wood alcohol is usually made from fossil fuels, but it can also, as the name suggests, be made by distilling wood, though the process is inefficient). So far, so good. 

 

The basic recipe is simply to pass a mix of air and methanol vapor over a bed of silver powder at 1000 K (campfire temperature) and atmospheric pressure, and then capture the resulting formaldehyde gas in water. Other catalysts like platinum wire can be used in place of the silver. That's all sounds perfectly achievable, and I think any aspiring alchemist with a reckless disregard for lab safety could probably rig up a sketchy bootleg swampwitch version of the process.

 

In fact, yes, here is one such sketchy bootleg swampwitch attempt to brew formaldehyde.
Oh golly, this one here is even more sketchy and swampwitchy.

 

Besides, any self respecting wizard needs formaldehyde for their jars of twitching magical eyeballs. So sure, fantasy formaldehyde is a go go. What can you do once you have some formaldehyde?

You can make plastic from milk.

Casein is the stuff in milk that's good for your teeth. Turns out, formaldehyde can react with casein, linking it together into long chains. The resulting material was called Galalith, meaning "milk stone", and was machined into jewelry and buttons.

 

 

A lovely little knickknack made from milk.

Here's a very minor annoyance: Many of the videos on YouTube about milk stone are not actually about milk stone. The milk plastic that they make is a weak crumbly mess which just looks like dried cheese. And this is because it is dried cheese. Instead of using formaldehyde to link together casein molecules, they just curdle whole milk, squeeze the liquid out of the curds, press them into shape, and then leave it to dry. That's a recipe for cottage cheese, except for the part where it's left on the windowsill for several days.  You can technically call it a plastic, I guess. But it's not galalith, you guys. It's  stale cheese. You need to throw that away.

Shout-out to Robert Murray-Smith for being one of the few channels with videos actually about making casein bioplastics.

Anyways, milk stone was hot stuff for much of the first half of the twentieth century, but was eventually displaced by the development of newer, cheaper materials with better physical properties. Galalith is still sometimes used to make buttons for clothes, however.

 

Bakelite is made of formaldehyde too.

Bakelite is some lovely stuff. For a while there back in the day, basically everything was made out of the stuff. I even have a couple of board games on my shelf made out of Bakelite. 

Bakelite was the earliest fully synthetic resin, developed as an alternative to lac, which is a naturally occuring resin that the lac beetle just sort of... oozes out. 

 

Bakelite is made by mixing formaldehyde with phenol, which is one of the earliest chemical antiseptics. But here we run into a major snaggle because phenol originally comes from coal tar. That works great in the real world, but if your world is only 300 years and rests on the back of a giant turtle, it's going to be hard to find some fossil fuels. 

 

It is possible to make phenol from salicylic acid instead, which is an important medicine originally derived from the bark of the willow tree. But such a limitation would probably make bakelite a lot less common.

 

Carved Bakelite and Galalith bangles, from Cheryl on Flickr

 

Guess what else you can mix with formaldehyde.

But as it turns out, phenol-formaldehyde resins aren't the most commonly used kind of formaldehyde resins. That honor goes to urea-formaldehyde resins. What's urea, you ask?

 

It's piss.

While most urea nowadays is synthesized from natural gas, the process of isolating urea crystals from urine was discovered all the way back in the 1200s. Definitely within the bogwitch toolkit.

UF resin can be molded into solid shapes, but is most commonly used in combination with cellulose. It's mixed in with bits of wood to form particle board. And it's used as a strengthening additive to  paper, cotton, and rayon. It used to be used on its own as foam insulation, but there were concerns about formaldehyde gas being released into homes.

Objects made of UF. Photo from user geni on wikimedia

 

There are also higher quality melamine-formaldehyde resins. When you write on a white-board, it's likely you're writing on MF resin. Melamine is created from urea, but that process seems a bit outside of bogwitch territory, with this slideshow describing a "low pressure version" that still needs ten atmospheres of pressure, which is about the same as inside a steam train's boiler.  Secret chemistry knowledge from the future? Sure, throw that into a generic grungy fantasy world. Pressurized steel reaction vessels? That's sliding into steampunky territory.

 

 Note to self: formaldehyde-themed wizard school? "Formalin witchcraft"?

 

 

 

 

 

 

III - Ethylene - a heck of a thing.

The bulk of the plastics in the world today are derived from a monomer called ethylene (or ethene). In fact, by volume, humanity manufactures more ethylene than any other organic molecule (unless we're counting agriculture as manufacturing, in which case obviously cellulose wins again).

 

Behold ethylene! The foundation of your modern world!

Ethylene is some sweet stuff.

Ethylene on its own is a simple gas which naturally occurs in small amounts.

 

It's an important hormone that triggers aging in plants. It's what causes flowers to develop and fruit to ripen. It's also what causes leaves to fall from trees. My spouse is very particular in how they store fruit, claiming for example that putting apples next to the kiwis will make the kiwis taste sweeter. Turns out, that's not just a weird tradition from grandma; apples fart out ethylene! Small scale ethylene production is often used for this purpose, generating ethylene gas in an enclosed room to rapidly ripen fruits.  

Old-timey kerosene lamps produce small amounts of ethylene in their smoke, leading to a bizarre phenomenon in the late 1800s and early 1900s where street lights were killing the trees along city streets.

 

Oh yeah, and it's also psychoactive. It smells sweet and induces euphoria when inhaled, so was tried for a time as an anesthetic alternative to chloroform. Doctors stopped using it that way as soon as better alternatives were found. There's also speculation that the prophetic visions of the Oracle of Delphi were triggered by ethylene inhalation.

 

Huffing ethylene, seeing the future, and having a great time.
John Collier - Priestess of Delphi - 1891

 Finally, it shouldn't surprise you to learn that the stuff can explode at high concentrations.

 

Making ethylene in bulk. 

The main source of ethylene production is, sure enough, from fossil fuels. You take some propane or whatever, heat it up with some steam, and you're off to the races. The process is called steam-cracking. The temperatures are reasonable, and the pressures are atmospheric. The difficulty is that to stop the reactions and end up with the chemical you want, the gas has to be rapidly cooled and compressed, something only possible with twentieth-century refrigeration technology (but maybe not an issue for an ice mage?).  Plus, you know, fossil fuels.

Luckily, there are other sources of the substance as well. As mentioned above, it can easily be made from ethanol. Ethanol (the stuff in wine that gets you drunk, or "aqua vitae" as an alchemist might call it) is the hydrate of ethylene. To vastly oversimplify, ethanol = ethylene + water, and converting between the two is fairly straightforward. In fact, the supply chain can go either way:

Until about 1950, ethylene was expensive and was obtained from fermented ethanol by dehydration - the reverse of the above processes. With the advent of cheap ethylene from steam cracking, the petrochemical route to ethanol became more economical than fermentation. By the early 1970s, scarcely any industrial ethanol was made by fermentation in the United States, although there was a legal requirement in most countries that potable ethanol be made in the traditional way.
    In the United States in the 1980s, this trend was reversed when government subsidies were introduced to facilitate the production of ethanol by fermentation of corn starch. The product went into automotive fuel known as gasohol.
    ...
    With the advent of huge production facilities for fermentation ethanol, new plants have been built in Brazil for its dehydration to ethylene.   

-From Industrial Organic Chemicals, 3rd edition (Wittcoff Reuben Plotkin 2013)

There are a few ways our alchemist could transform ethanol into ethylene. 

The most straight-forward approach is to mix ethanol and sulfuric acid and heat the mixture up to 170 C. But that's like double the normal boiling point of these liquids, and you already know about my reluctance to put high-pressure chemistry inside of a wizard tower or witch's hut. 

However, if you do want to lean into the steampunky aesthetic, then take a look at the letter from 1779, in which the writer discusses their attempts to build a pneumatic pistol using "Vitriolic æther", which is a "very powerful inflammable air" extracted from "equal quantities of oil of vitriol and spirit of wine". I'm think the stuff described in this letter is just ether though, not ethylene.

A more common approach is to simply run ethanol vapors over a bed of alumina powder. 1 2 3  The gas that bubbles out will be ethylene. Alumina nowadays is made via the fancy schmancy Bayer Process, but alumina was originally discovered simply by boiling some clay in sulfuric acid and then neutralizing the result with lye. Totally bogwitchable. In fact, here's a youtuber making alumina in an open air crock pot cauldron:

But actually, it might be even easier than that. In the Cody's Lab video above, he mentions that most of the effort he's going through in isolating the alumina is to get rid of the silica, but silica is fine or even desirable for a ethanol dehydration. So maybe you just need dry clay? The right kind of dry clay at least? 

 This all sounds very doable for a witch, and even if you don't collect enough ethylene to create plastic, as the very least you can use it to curse a tree or something.

 Tangent: Check out the bizarre copy on this ethylene generator. Firstly, they advertise that their product, "when used as directed, cannot cause explosions". Secondly, they're selling their own super special fluid to put in the thing, called "Ethy-Gen® II Ripening Concentrate", resplendent with buzzwords, but then you look at the ingredients and sure enough it's pretty much just ethanol.

Okay, enough about the monomer. Let's get back to the polymers! 

 

Turning ethylene into other stuff.

Once you control the ethylene, you control the universe.

 

From the Guide to the Business of Chemistry by the American Chemistry Council

 

Polyethylene is bunch of ethylene hooked together, and is the most common kind of plastic. You're probably touching some of it right now. There are several different kinds of it, and all of them have some feature that makes them difficult to translate to an alchemistish context. After all, there's a ton of ethylene floating around in nature. If it were easy to polymerize the stuff, you'd think polyethylene would show up in living creatures.

 

Low Density Polyethylene is flexible plastic made by simply compressing and heating ethylene. But this requires pressures of thousands of atmospheres.

High Density Polyethylene (which is harder and more rigid than LDPE) can be made at near-atmospheric pressures and relatively low temperatures, but the process requires fancy schmancy catalysts. "Chromium? Titanium? Never heard of em," says the bog witch.

Linear Low Density Polyethylene is a successful attempt to make flexible Low Density PE using the more reasonable temperatures and pressures of the HDPE process. In addition to those weirdo future catalysts, LLDPE requires a intermediate step where some of the ethylene is processed into oligomers like this chemical which has the official name of "But-1-ene".

PolyVinyl Chloride is usually just called vinyl. It's the third most common modern plastic. The vinyl monomer can be made by from reacting chlorine with ethylene over hot pumice, then the vinyl monomer is pressurized to 13 atmospheres and heated to make the vinyl polymer. In the textbook I was reading, it seems like most of the effort in synthesizing vinyl is finding a way to deal with the horrible awful deadly toxic byproducts. Not a problem for a wizard, who can just summon a magical gale to carry the cloud of hydrogen chloride away from their tower and towards the local puppy orphanage.

Gunshow - KC Green

 

Polyproylene is the second most common polymer being churned out. The monomer propylene isn't typically made from ethylene, but it is possible to do a convoluted multi-stage conversion, which seems to be the only way of making the stuff without using fossil fuels. Regardless, the subsequent conversion to a polymer requires moderately high pressures and some of those same weird catalysts.

Polyesters are a large group of polymers, but the term is often used to refer specifically to PET, short for PolyEthylene Terephthalate. PET is the fourth most common synthetic polymer, and is made from ethylene in several steps. First, ethylene is combined with oxygen over a silver catalyst at 15 times atmospheric pressure to form ethylene oxide. The ethylene oxide is then  mixed with water to form ethylene glycol and a bunch of other stuff which has to be filtered out. (The ethylene glycol is useful on its own as antifreeze.) The antifreeze is then combined with terephthalic acid under heat and pressure to form PET. The terephthalic acid can be extracted in small amounts from natural sources like turpentine, but is made in bulk from para-xylene using yet another exotic catalyst, and the para-xylene comes from fossil fuels. There are ways to make para-xylene from wood, but the processes are new and require yet more strange catalysts. Oh gosh, this is a bit much. What is Lanthanum? I genuinely forgot that was an element, but you're apparently going to need some if you want to make polyester without fossil fuels.

 

And I'll call that good for now. I guess I'll just write off the bulk of modern plastics as being too modern for an alchemist. But at least I learned about ethylene and now have an excuse to give Fireball to fruit-themed wizards.

 

IV - Scleroproteins - The real polymers were inside you all along

DNA is also technically a polymer, made of monomers called nucleotides, storing information in the form of a long chain. And all proteins are polymers because they are constructed by translating DNA sequences into chains of amino acids. 

But Scleroproteins are the proteins that behave the most like what we would typically call "plastic". They're very long proteins that connect together into sheets or fibers. Important scleroproteins include collagen, keratin, fibrin, and elastin.

Collagen is the most common protein in the human body. It's tough and flexible, and makes up ligaments, tendons, cartilage and blood vessels. When mixed with a mineral called hydroxyapatite, it forms bones and teeth. The name means "glue-maker", because we can boil it down to make some kinds of glue.

Keratin: Long coiled protein polymers used to make claws, fingernails, hair, feathers, reptile scales, tortoise shells, and rhino horns. It's very hard and tough. If a part of your skin is repeatedly subjected to stress, your body will put some keratin in the skin there to form a callus.

 

Can also be boiled down into a polymer-based glue

Fibrin helps you stop bleeding when you are injured. First it blocks the damaged blood vessel to slow the flow of blood, and then it's used to build a protective scab to cover the wound while its healing.

Elastin: Kind of like our body's version of rubber. It's what makes our lungs and bladder so stretchy, and its mixed with collagen to help absorb shocks. Our skin contains elastin fibers, and the loss of these causes our skin to get saggy as we age.
 

 

 

 

 

Summary:

Here are a few naturally occurring plastic polymers. A powerful enough wizard can just magically reshape crabs into dishware and skip all the industrial chemistry stuff:

• Chitin: Sugar polymer. The plasticy stuff bugs and other arthropods are covered in. Mushrooms also use the stuff for cell walls. 
• Cellulose: The most common polymer. Found in plants. Sugar-based. Cotton and paper are made of the stuff.
• Wood: Mix of cellulose and lignin, which is another more complicated plant polymer that holds the cellulose together. 
• Lac: It has basically all the properties that we associate with modern synthetic plastics, but it comes out of a bug. Weird.
  
• Scleroproteins: Tooth, horn, bone, hair, tendons, animal glue, scabs. All sorts of rad stuff.
  

 Plastic polymer materials reasonably available to your standard deranged witch living in a bog:

• Chitosan: Humanity's best attempt so far at making stuff out of chitin. Made by mixing shrimp shells and lye.
• Rayon and Cellophane: Regenerated cellulose. Take some cellulose, and break it down using lye, sulfur, and charcoal. Dissolve the result in more lye, let it "ripen", and then extrude it into some sulfuric acid to turn it back into cellulose. 
  
• Nitrocellulose: First man-made plastic. Made by soaking cellulose in a simple mix of alchemical reagents. Still looks and feels like cotton but now it explodes and can be easily dissolved to turn into lacquer for things like nail polish.
• Celluloid: Nitrocellulose mixed with camphor. Less explosive, and can be injection molded or turned into film reels.
• Galalith: Cheese protein treated with formaldehyde, more or less. Another of the earliest synthetic plastics. Waterproof, hard, and looks nice, but very brittle. It's really only good for small knick knacks like buttons. 
• UF Resins: Urea, formaldehyde, and a bit of acid. Mostly used as a binder in wood or an additive to fabric instead of on its own.

Some other plastics which might be harder to get your hands on without modern industry:

• Cellulose Acetate: Safety film. Made by soaking cellulose in sulfuric acid, acetic acid, and acetic anhydride. It's that last ingredient that would be difficult to get.
  
• Bakelite: First synthetic resin. Developed as an alternative to lac. Used to be used for all sorts of stuff. An example of phenol-formaldehyde resins. Phenol originally comes from coal tar, which is a snaggle for the "no fossil fuels" bit of worldbuilding.
  
• MF Resins: Like a higher quality version of UF resins. Melamine is used instead of Urea. And while Melamine is made from urea, it needs moderately high pressures.
  
• Ethylene-derived plastics: Which is to say, pretty much all of the modern plastics. These can all be made without fossil fuels by starting with fermented ethanol. But the process of making the polymers either involves high pressures or exotic catalysts or both.
  

Links

This was by no means a comprehensive guide to industrial chemistry. Didn't even get around to talking about rubber. This was just an amateur exploration, focused on the framing device of "What could a medieval alchemist actually make, given the right recipes?"

Here are some links I found very useful, and might be useful if you want to read more about plastic and whatnot:

• Guide to the Business of Chemistry by the American Chemistry Council. There are some great appendices at the back.
• Industrial Organic Chemicals, 3rd Edition, by Wittcoff, Reuben, and Plotkin. A textbook that I found enjoyable as a lay reader. Includes lots of details about chemical reactions, of course, but also about the history, politics, and economics of chemistry as well. Expensive, but maybe you can find a copy in the library like I did.
• The Essential Chemical Industry Online. A lovely little reference website, and a good starting point if you want to learn about a particular chemical.
  
• Here's their index on basic chemicals.
• And here's their index on polymers.