Synthetic Rubber (2)
The first people to put rubber to use were the indigenous peoples of Mesoamerica. Among the earliest civilizations of that land were the Olmec — their very name a corruption of the Nahuatl word olmecatl, meaning "rubber people." When the Aztecs later uncovered their ruins, they found rubber trees in abundance. They would dip their feet in the sap, let it harden, and trim away the excess to fashion rubber boots of their own.
The American inventor Charles Goodyear, struck by rubber's waterproof qualities, fashioned rubber mailbags — only to watch them melt in the summer heat, costing him a fortune. His colleague N. Hayward, hunting for a way to make Goodyear's invention practical, discovered that treating rubber with sulfur kept it from turning sticky.
Then one day Goodyear accidentally dropped a piece of sulfur-treated rubber onto a hot stove, and found, to his astonishment, that the rubber did not melt. It grew tougher and more resilient instead. Goodyear and Hayward systematized the curing process and patented it in 1844.
Ironically, about eight weeks before Goodyear filed that patent, something extraordinary happened. The British inventor Thomas Hancock patented the same sulfur process — naming it vulcanization, after Vulcanus, the Roman god of fire.
Many scholars have argued that Hancock reverse-engineered Goodyear's samples and beat him to the patent office. Hancock himself denied the rumor outright. The truth remains buried. But when something fishy happens in world history, if you just put your finger on Britain, you're usually close enough. I've always been fond of that story.
In any case, once vulcanization was discovered, the uses for natural rubber exploded. Rubber was hailed as a material of the gods — waterproof, windproof, dustproof, soundproof, elastic, and flexible. And when the automobile industry took off in the twentieth century, demand for it skyrocketed. Every nation scrambled to secure natural rubber, and, failing that, to find a way of making rubber without it.
Germany, which had learned the hard way what a rubber shortage meant in wartime, poured every ounce of national capacity into developing a new synthetic rubber, with IG Farben at the center of the effort. The first technologies they set their sights on were Soviet petrochemical processes.
In 1901, IG Farben's chemists produced Germany's first synthetic rubber — methyl rubber — based on Ivan Kondakov's theories. By today's standards it was commercially worthless, and the market quietly buried it. What caught their eye next was Lebedev's method of polymerizing butadiene into synthetic rubber.
In this way, Germany's early synthetic rubber research leaned heavily on processes pioneered in the Soviet Union. After years of work, they would go on to invent SBR — Buna-S rubber — leaving a mark so deep that the period up to 1960 would be known as the "SBR era."
"If we emulsion-polymerize styrene and butadiene at a ratio of one to three, we should be able to produce a synthetic rubber whose composition is nearly identical to natural rubber...?"
Styrene-butadiene rubber — SBR for short, also called Buna-S. In time, this synthetic rubber would claim more than half the world's automobile tire market. Geopolitically starved of natural rubber, the Soviet Union could live off it as a strategic staple. And since both styrene and butadiene could be extracted from the thermal cracking of naphtha and diesel, or from the manufacture of ethylene, it would be all the more efficient in a Union awash in crude oil.
"You... just where did you get this information? Don't tell me you brought back a technology some other country already invented?"
"That's not it."
I shook my head. In fact, about a year from now — in 1926 — Germany would develop a prototype called Buna rubber, but Buna-S itself would not be produced until 1929.
"Rubber made from butadiene alone stretches well enough, but it has no elasticity. Once I noticed that, it came to me all at once."
I pressed down hard on the squishy, jelly-like lump of early butadiene rubber and went on.
"What if we emulsion-polymerized styrene — an aromatic hydrocarbon in which one of ethylene's hydrogens is replaced by a benzene ring — along with it?"
Lebedev started, then stroked his beard.
"Styrene hardens gradually when exposed to air, light, or heat. So what you're saying is that adding styrene to butadiene would give you a polymer with the elastic properties of rubber?"
"...Yes. That's right."
"And emulsion polymerization, at that... Using water as the medium would make it easy to bleed off the heat of reaction. Wait — what would you use as the initiator? Potassium persulfate? Hydrogen peroxide?"
"W-wait a moment. I don't know it down to that level of detail, Professor!"
"...Ah. Right. I'd completely forgotten you weren't a specialist."
I knew that the initiator used in emulsion polymerization needed to be water-soluble. Beyond that, I was out of my depth.
Redox polymerization — cold polymerization — could dramatically extend tire life compared to conventional hot-polymerized rubber. But that was a technology the Soviet Union of the 1920s simply did not have.
The first generation of cold polymerization wouldn't arrive until 1940 at the earliest. With Soviet petrochemical engineering still in its infancy, the idea would have to remain a theory.
Lebedev said nothing for a long moment. He looked from the squishy lump of butadiene rubber to me and back again, then drew paper and a pen from his coat and began to write.
"Très... bien?"
"Ah — a French exclamation. Means 'very good.' I spent a stretch at the Sorbonne before I came to Leningrad, and it still slips out. I've tried to break the habit. Can't be done."
He rubbed his mustache, looking faintly sheepish.
Strictly speaking, chef-d'oeuvre was a French word too. Not that it mattered much.
"If your SBR turns out to be a worthy substitute for natural rubber... I shall personally introduce you to Comrade Stalin! I'll tell him a genius of chemical invention has been born in the Union."
"...Come again?"
"Don't tell me you don't know who Comrade Stalin is?"
No. I know him far too well.
"That's what everyone calls the General Secretary of the Union."
"I-I see..."
I had not expected Stalin's name to come out of Lebedev's mouth. And he clearly had no idea that the reason I'd gone pale was that Stalin was my father.
"W-why don't we leave the synthetic rubber for now and finish talking about the toluene adhesive?"
"Ah... quite right. The conversation wandered off on us. The emulsion polymerization of styrene and butadiene will take three months at the least, so we'll come back to it later. Wait here a moment."
Lebedev vanished through a small door behind the lab bench. Only then did I realize there was another room attached on the far side.
A clatter came from inside.
"What have you been doing all this time? Get it out here, now!"
"Aaaagh! P-please, spare us...!!!"
The sound of glass knocking together, of things being rummaged through, of screams tangled up with shouting — and over it all, Lebedev's bellowing.
What on earth is going on in that room?
A moment later, Lebedev came back with a group of people I had never seen. They wore lab coats stained past any hope of washing. Their hair looked as though it hadn't been touched in days, every one of them hollow-eyed, every face heavy with dread.
"...People?!"
They caught sight of me and hesitated.
"These fellows helped me make the toluene adhesive. My assistant professors. Introduce yourselves."
Not one of the people Lebedev introduced looked as though he had the strength left to say hello. One of them, catching my eye, worked his mouth without a sound. Looking closer, I could have sworn he was saying, Run. Get out of here.
"What are you standing around for? Put those down, now!"
"Y-yes, Professor!"
Startled by Lebedev's bark, they hurriedly set the crates on the bench.
...Ah. I see. They weren't graduate students. They were slaves. Nearly had me fooled.
Lebedev and his slaves — that is, his graduate students — pulled the test blocks from the crates, affixed the rubber, and slathered them with toluene adhesive. He'd already prepared several prototype toluene adhesives before I'd even arrived. That told me just how seriously he'd taken the problem.
This is going to work. No question.
"This one is toluene alone. This one has a little rosin mixed in. And this..."
Of course, behind all of it was the blood and sweat of his graduate students. The only thing I could do for them was say a quiet prayer for their souls.