Polypropylene and polyethylene
Polypropylene and high-density polyethylene plastics — the plastic that made the Hula Hoop® possible — discovered in 1955.
Phillips Petroleum Company in Bartlesville, Oklahoma, entered the plastics business in 1951, following a discovery by researchers J. Paul Hogan and Robert L. Banks. The two researchers had been looking for ways to convert ethylene and propylene – hydrocarbons produced when refining natural gas – into components for gasoline. In the process, they found the catalyst that would transform these products into solid polymers. The plastics that resulted – crystalline polypropylene and high-density polyethylene – are now the core of a multibillion-dollar, global industry.
Phillips introduced high density polyethylene in 1954, under the brand name Marlex® polyethylene. Company marketing executives were wildly optimistic, expecting that the product would be a big hit and that the Phillips would not be able to keep it on the shelves. But the market had become large and diverse and Marlex® then produced in only one grade, was unsuitable for some applications. Inventories piled up in the warehouses.
The turnaround came from an unlikely source — a large ring of plastic tubing called the hula hoop. This children’s toy became so immensely popular that the demand for Marlex® soared, taking the plant’s entire output for nearly six months.
The hula hoop craze helped pave the way for more practical uses, such as commercial and industrial tubing. In time, Marlex® also became the preferred plastic for baby bottles (because of its ability to withstand the high temperatures of sterilization) and for safe, shatterproof containers for food and other household products.
Visit National Historic Chemical Landmarks to read more about the discovery of polypropylene and polyethylene.
Excerpted with permission, National Historic Chemical Landmarks Program