Uses of Plastics

Plastics emerged in the prewar period, though some would not come into widespread use until after the war.
By 1936, American, British, and German companies were producing Polymethyl methacrylate (PMMA), better known as acrylic glass. Although acrylics are now well known for their use in paints and synthetic fibers, such as fake furs, in their bulk form they are actually very hard and more transparent than glass, and are sold as glass replacements under trade names such as "Perspex", "Plexiglas" and "Lucite". These were used to build aircraft canopies during the war, and its main application now is large illuminated signs such as are used in shop fronts or inside large stores, and for the manufacture of vacuum-formed bath-tubs.
PEs are cheap, flexible, durable, and chemically resistant. LDPE is used to make films and packaging materials, while HDPE is used for containers, and automotive fittings. While PE has low resistance to chemical attack, it was found later that a PE container could 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 an improved material, Polypropylene (PP), which was discovered in the early 1950s by Giulio Natta. It is common in modern science and technology that the growth of the general body of knowledge can lead to the same inventions in different places at about the same time, but polypropylene was an extreme case of this phenomenon, being separately invented about nine times. The ensuing litigation was not resolved until 1989.