An Introduction to the History of Plastics A Plastics Explosion - Polyethylene, Polypropylene, and Others Other plastics emerged in the prewar period, though some wouldn't come into widespread use until after the war. By 1936, Amer ican, British, an d German compa nies we re pr oducin g "polymethyl m ethacrylate" (PMMA), bette r known as "acrylic." Although acrylics are now well-known for the use in paints and synthetic fibers, such as "fake furs," in their bulk form they are actually very hard and more transparent than gl ass, and are sold as gl ass repl acements un der trade names such as "plexiglas" and "lucite." Plexiglas was us ed to build aircraft can opies during the war, an d it is al so now us ed as a ma rble repl acement for countertops. Another important plastic, polyethylene (sometimes known as "polythene") was discovered in 1933 by Reginald Gibson and Eric Fawcett at the British industrial giant Imperial Ch emical Industries (ICI). This material ev olved into two forms, low den sit y pol yet hylene (LDPE) and high densi ty pol yet hyl ene (HDPE) . Polyethylene is c heap, flexible, durable, a nd chemically resistant. LDPE is used to make films and packaging materials, including plastic bags, while HDPE is used more often to make containers, plumb ing, and automotive fittings. While PE has low resistance to chemical attack, it was found later that a PE containercould be made much more robust by exposing it to fluorine gas, which modified the surface layer of the container into the much tougher "polyfluoroethylene." Polyethylene would lead, after the war, to another material, "polypropylene" (PP), which was discov ered in the early 1950 s. It is common in modern scienc e and technology that the growth of the general body of knowledge can lead to the same invention s in dif fe rent places at about th e same time, but pol ypropy lene was an extreme case of thi s phe nomenon, bei ng separatel y inv ent ed about nine times. It was a patent attor ney 's dream scenario, and litigation wasn't resolved until 1989. Polypropyl ene managed to survive the legal process, and two American chemists working for Phillips Petroleum of the Netherlands, Paul Hogan and Robert Banks, are now gen era lly cre dit ed as the "of ficial" inv ent ors of the mater ial. Polyp ropy lene is simi lar to its ancesto r, poly ethyl ene, and shares polyethylene's low co st, but it is much more robust. It is used in eve rything from pl astic bottles to carpets to pl astic furniture, and is very heavil y used in automobiles. Pol yur ethane was invent ed by Fri edr ich Bay er & Compan y of Germany in 1937. It would come into use, aft er the war , in blown form for mattresses, furniture padding, and th ermal insulation. It is also used in non-blown form forsports wear such as "lycra."
