PE did not immediately succeed. Although ICI first commercialized it in 1939, the demand has been increasing slowly. It was not until the early 1950s that the market realized the usefulness of the product in packaging applications.
When a new type of PE emerged in the mid-1950s, demand was once again boosted. The two products are chemically the same, but their properties are different. The original PE is soft as wax, easy to stretch and deform. The new polyethylene is strong, hard, and heat resistant.
The reaction conditions are responsible for this difference. The oxy-based initiator is used for production under high temperature and high pressure, and a polymer main chain of chemical manufacturer with light branches is obtained. The new transition metal catalyst makes it possible to produce polyethylene under low-temperature and low-pressure conditions. This makes polyethylene have a basic linear backbone without branches and makes the molecules more compact. Therefore, the new product is called high-density polyethylene (HDPE), while the original type is called low-density polyethylene (LDPE).
Paul Hogan and Robert Banks of Phillips Oil Company were the first to synthesize this new material. In 1951, when the two were looking for a way to convert propylene into gasoline components, the chromium catalyst produced surprisingly crystalline polypropylene (PP). As for ethylene, they soon discovered that the same catalyst can also be used to make HDPE. Since then, every product has become the cornerstone of the petrochemical market.
Karl Ziegler, a chemist at the Max Planck Institute in West Germany, discovered in 1953 that titanium-based catalysts could produce HDPE. Giulio Natta, who works for Montecatini, Italy, took Ziegler's discovery one step forward, using similar catalysts to make crystal PP.
The commercialization of HDPE is not smooth. Phillips introduced HDPE to the market as Marlex in 1954, producing it at a new $50 million factory in Houston. According to chemist Charles Carraher, expectations are high, but the company is having trouble keeping materials up to specifications. Buyers are indifferent to this, and products are accumulating higher and higher. However, the Hula Hoop toy launched by the Huim-Ou Company in 1958 gave Phillips a respite. Wham-O believes that Malex is completely suitable for its new products. The toy manufacturer bought everything that the factory can produce within one and a half years, giving Phillips time to solve the problems in the process.
By 1957, several other manufacturers were also using transition metal catalysts. The HDPE is manufactured in Houston by Celanese; the Hercules in Palin, New Jersey; and the WR Grace in Baton Rouge, the PP is manufactured by Montecatini in Ferrara, Italy; Hearst is in Frankfurt ; With Hercules in Palin. Before the end of this decade, chemists created another form of polyethylene, linear LDPE. DuPont first started production in Corunna, ON in 1960.
DuPont was particularly busy in the 1950s. The company began to produce polyester in 1950, which is called polyester. In its Seford, DE plant, it has an annual output of 1.5 million pounds. In 1953, the company invested 40 million US dollars in Kingston, North Carolina. A factory. DuPont introduced polyester film in 1952. The company started to produce Aulon acrylic yarn in 1950, and began to produce Aulon acrylic staple fiber in 1952. DuPont started producing polyacetal in 1959 and named it Delrin.
Another important polymer, polycarbonate, began production in 1958 by Bayer and GE Plastics.
Round the clock: Workers arrive at DuPont's Sabine River plant in Orange, Texas, and begin night shifts. Photo courtesy of Hagley Museum and Library.
The petrochemical industry began to take off in the 1950s. Coal has long been the main source of organic chemicals, but the growing petroleum industry provided alternative energy sources, and World War II accelerated their development. This trend is particularly obvious in the United States. At the end of the war, the United States gathered a strong and young petrochemical manufacturing base on the Gulf Coast. By 1950, the industry had gained a firm foothold and, driven by the growing demand for synthetic resins and rubber, it quickly spread to all parts of the world and became a modern material.
Some figures indicate the speed of change. According to Ullmann's "Encyclopedia of Industrial Chemistry", in 1940, the total global plastic production was 360,000 tons. By 1950, this number had increased to 1.62 million metric tons, and by 1960, it had increased to 6.7 million metric tons-an increase of 300% in ten years. The production of synthetic elastomers increased from 43,000 metric tons in 1940 to 540,000 metric tons in 1950 and 1.94 million metric tons in 1960. The production of synthetic fibers increased from 5,000 metric tons in 1940 to 69,000 metric tons in 1950 and 700,000 metric tons in 1960.
Preface: World War II
Because of the Second World War, when and where did this prosperity appear. In 1940, although the petrochemical industry had a bright future, it was still a small part of the chemical industry. Since the 1920s, the company has been developing oil and natural gas-based chemicals, but market opportunities are limited. Although many potentially useful polymers have been discovered, commercialization risks are high.