It's 1932, and while Standard and I. G. Farben are busily working together to try and make Buna rubber a marketable product, another type of synthetic rubber is being born.

In April of this year, Frank Howard of Standard is visiting with Dr. Martin Müller-Cunradi of I. G. Farben. Dr. Müller-Cunradi hands Howard a jar of a clear viscous fluid, which, he says is a polymer of isobutylene, a well known by-product of oil refining. Howard knows that people had tried to polymerize isobutylene in the past, but had only succeeded in joining a few molecules. Long chain polymers had never been made, and high molecular weight is needed for good properties.

Curious, Howard visits to the research lab where he is shown the process for making this polymer. Liquid isobutylene is placed in an open beaker which is packed in dry ice. Dry ice is also placed in the beakers where it dissolves in the isobutylene. The catalyst, a little known gas called boron fluoride, is poured into the beaker, there is a small puff, and where there had been a beaker half full of liquid now stands a beaker overflowing with a spongy solid. This product can be taken out and handled like a soft snowball. That's all there is to it.

The butyl reaction

Howard takes this development back to the Standard research labs, where they work on it and call it Vistanex. It goes on sale in the winter of 1933 as a thickener for oils and greases, and works great, because it is less effected by temperature changes than ordinary oils, which makes it great for cars and hydraulic systems that experience large temperature fluctuations. Vistanex is also found to have some rubber-like properties, but it has no residual double bonds for vulcanization and is not strong or elastic enough in it's raw form to compete with natural rubber. Initially, the isobutylene used to produce Vistanex is synthesized, but research is being conducted on how to remove the isobutylene naturally present in refinery gasses, which is usually just burned.

Super Fuel

With the development of new and better automobile engines, new and better gasolines are needed. The increase in compression ratio of each new engine increases power output and fuel efficiency, but also increases the tendency of the low quality gasoline of the time to "knock" and "ping." Thomas Midgley of General Motors had recently discovered that adding tetraethyl lead to gasoline reduces this pinging tendency by increasing the octane rating. The octane scale has just been worked out by Dr. Graham Edgar of the Ethyl Corporation using isooctane as the standard. Isooctane has the interesting property of not knocking in any engine under any conditions. What does all of this have to do with Vistanex and synthetic rubber? Isooctane is made from isobutylene.

Now that the octane scale has been developed, every fuel company wants isooctane so they can rate their gasolines. Some even want to just use the isooctane as fuel itself for airplane and auto racing. They figure, "Why waste time with low grade gas if I can get the "super-fuel" that the whole rating system is based on?" With all of this demand, Standard quickly gets on the case. Soon they figure out that by purifying the refinery gases, diisobutylene and triisobutylene can be obtained. The diisobutylene can be hydrogenated using a modified form of the Bergius Process and the triisobutylene can be passed over a catalyst to form isobutylene, the starting material for Vistanex. Talk about killing two birds with one stone!

Of course, isooctane can be used as fuel alone, but to make it easier to handle and to make more of the "super-fuel" available, the isooctane is mixed with the highest quality natural gasolines. This lowers the octane rating below 100, but tetraethyl lead is added to bring it back to 100. The first batch of 100-octane super-fuel is made at Standard's Baton Rouge, Louisiana refinery in June, 1935. Soon, the US Army Air Corps is optimizing it's aviation engines for the new gasoline.

Spin Cycle

Dr. William J. Sparks

Robert M. Thomas

Researchers at Standard had been working for years tinkering with the process for making Vistanex. They had improved the product to the point that it was practically indistinguishable from raw natural rubber, but it still could not be vulcanized. Then, in 1937, Dr. William J. Sparks and Robert M. Thomas mixed up a batch of Vistanex in a washing machine they had picked up at the local department store. This time, however, they added a small amount of butadiene, the main ingredient in the synthesis of Buna rubber in with the isobutylene. When the spin cycle finished and the smoke cleared, Butyl rubber had been born.

This stuff was great! Butyl rubber holds air 13 times better than natural rubber, and has excellent resistance to aging, weathering, chemicals, moisture, ozone, temperature extremes, and tearing. It does not bounce at ambient temperatures, which makes it a great shock and vibration absorbing material, and best of all, the raw materials are plentiful, easily obtained, and cheap.

A. Donald Green

Sure this new rubber is great, but how can it be made on an industrial scale. Sparks and Thomas, being lab chemists, say that it should be made in a giant washing machine, a batch reactor. A. Donald Green, the engineer on the project, will not hear of such a thing. He had learned at the Massachusetts Institute of Technology that the most efficient and cost effective way of making chemicals is through a continuous process, and this is the process they choose. Initially, the rubber keeps clogging up the reactors, forcing frequent shutdowns. Not a very efficient and cost effective process. Eventually, the engineers get the kinks worked out, and in 1943, the first batch of Butyl rubber is produced for market at the Baton Rouge facility.

Next stop: Washington D.C. - Government Rubber

Meanwhile...

While Sparks and Thomas are cleaning the rubber out of their new washing machine in 1937, this is happening:

Construction on San Francisco's Golden Gate Bridge is completed.

John Steinbeck writes Of Mice and Men.

While docking in Lakehurst, NJ, the famous German airship, Hindenburg, explodes, marking the end of regular passenger airship service. "Oh, the humanity!"

1. Barron, Harry. Modern Synthetic Rubbers, 3rd ed. London: Chapman & Hall, Ltd., 1949.

2. Herbert, Vernon and Attilio Bisio. Synthetic Rubber: A Project That Had to Succeed. Westport, Connecticut: Greenwood Press, 1985.

3. Howard, Frank A. Buna Rubber: The Birth of an Industry, D. van Nostrand Company, Inc., 1947.

4. Purcell, Andrew T. and James V. Fusco. Butyl: The First Fifty Years. Exxon Corporation, 1987.