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A Brief History of the Discovery of Crystalline Polypropylene and High Density Polyethylene

J. Paul Hogan and Robert L. Banks
Inventors of Crystalline Polypropylene and High Density Polyethylene.

Natural Gas Liquids Research

The breakthroughs by J. Paul Hogan and Robert L. Banks in 1951 were made while attempting to convert light hydrocarbons like ethylene and propylene into gasoline. Much of this effort began under the direction of George Oberfell. As director of Phillips research, Oberfell convinced Frank Phillips on the value of research into additional uses for natural gas liquids. By 1927, Oberfell had established one of the world’s first hydrocarbon research laboratories. Early research in these laboratories led to the development of liquefied propane gas for household heating.

George Oberfell (inset) established one of the world’s first hydrocarbon research laboratories in 1927. Oberfell came to Phillips in 1925 to defend the company against a patent infringement lawsuit filed by Union Carbide.

Discovery

In the early nineteen fifties Hogan and Banks were progressing in their goal of converting ethylene and propylene to gasoline. However, in 1951 they made discoveries that would eclipse their earlier work. They discovered a new material, crystalline polypropylene. In addition, a process for the production of a new high-density polyethylene was discovered. This material was much stiffer, harder and more heat resistant than the polyethylene being made at the time.

The laboratory, now known as 84-G, was located on the "Island" at the newly established Phillips Research Center. The "Island" got it's name because the stream that surrounded it would flood after heavy rains, separating it from the other parts of the research center. The trees in the above photo are growing on the banks of that stream.

In addition to providing the world with two new materials, the catalysts Hogan and Banks invented converted ethylene to polyethylene at pressures tens of thousands of psi lower than existing technology. The only technology for producing polyethylene at that time was a free radical process requiring pressures of 20,000 to 30,000 psi. These new catalysts produced polyethylene at only a few hundred psi.

Robert L. Banks and J. Paul Hogan receiving the ACS Perkins Medal in 1987

Development

During the development of these inventions Phillips scientists and engineers faced numerous and difficult technical challenges. Reaction conditions had to be tightly controlled to produce the desired products. The feedstocks had to be carefully purified and handled to minimize contaminants that significantly reduced catalyst performance. These challenges were overcome through teamwork and many long hours. In 1955, one year after the start of pilot plant development, Phillips management approved the building of a new 75 million pound per year polyolefins plant. In a span of only six years, this laboratory discovery was brought to commercial production. In 1959, Phillips introduced a dramatic improvement on its initial process technology. The Phillips slurry loop reactor quickly became tHe industry standard for high density polyethylene process technology.

Last Updated February 18, 2001