History of Polyolefins

Abstract

The history of polyolefins actually began in the 1890s with the synthesis of polymethylene from diazomethane. In the 1930s researchers in England discovered that ethylene at high pressure and in the presence of oxygen polymerized to a high molecular weight resin. Further research there and in the United States at still higher pressures yielded essentially straight chain, higher density polyethylenes. Early in the 1950s, groups in the United States and Europe independently discovered that linear, high-density polyethylenes could be made at low pressure over heterogeneous catalysts. Concurrently, groups catalytically produced polyolefin plastics from propylene and higher a-olefins. The inventorship of crystalline polypropylene was awarded to Phillips Petroleum Co. by United States courts in early 1980 (subject to final appeal). Commercial production of low-density polyethylene began in England (ICI) in 1939. High-pressure plants appeared in the United States (Du Pont and Union Carbide) and in Germany during World War II. Production of linear polyethylene started in late 1956 in the United States (Phillips). A semiworks Koppers plant began polyethylene production for commercial use earlier in 1956. Other plants quickly followed suit, using Phillips and Ziegler processes. Polypropylene production began in Europe and in the United States in 1957-1958. Two other polyolefin plastics have been produced in small commercial quantities, starting about 1965: poly(4-methyl-l-pentene) and poly-1-butene.