Materials that can be shaped by applying heat or pressure. Most plastics are made from polymeric synthetic resins, although a few are based on natural substances (e.g. cellulose derivatives or shellac). They fall into two main classes. Thermoplastic materials can be repeatedly softened by heating and hardened again on cooling. Thermosetting materials are initially soft, but change irreversibly to a hard rigid form on heating. Plastics contain the synthetic resin mixed with such additives as pigments, plasticizers (to improve flexibility), antioxidants and other stabilizers, and fillers.
PLASTICS
1851 | Scottish chemist Charles Macintosh (1766–1843) makes ebonite (from rubber). |
1855 | British chemist Alexander Parkes (1813–90) patents Parkesine, a plastic made from nitrocellulose, methanol, and wood pulp; it is later called ‘celluloid’. |
1860 | British chemist Charles Williams (1829–1910) prepares isoprene (synthetic rubber). |
1868 | US printer John Hyatt (1837–1920) develops commercial process for making celluloid. |
1884 | French chemist Hilaire de Chardonnet (1839–1924) develops process for making rayon. |
1892 | British chemists Edward Bevan (1856–1921) and Charles Cross (1855–1935) develop the viscose process for making rayon. |
1899 | British chemist Frederick Kipping (1863–1949) discovers silicone plastics. |
1901 | German chemists Krische and Spitteler make formaldehyde–casein plastic (Galalith). |
1905 | Belgian-born US chemist Leo Baekland (1863–1944) invents Bakelite. |
1912 | Swiss chemist Jacques Brandenberger produces Cellophane (viscose cellulose film). |
1913 | US Formica Insulation company markets plastic laminate made from formaldehyde resins. |
1918 | Hans John prepares urea–formaldehyde resin. |
1926 | German chemist Hermann Staudinger (1881–1965) discovers the polymeric nature of plastics. |
1930 | US chemist Waldo Semon develops PVC (polyvinyl chloride). |
1930 | Canadian chemist William Chalmers discovers polymethylmethacrylate (Perspex and Plexiglass). |
1930 | German chemists at IG Farbenindustrie produce polystyrene. |
1931 | Wallace Carothers invents nylon. |
1938 | US chemist Roy Plunkett produces polytetrafluoroethene (PTFE). |
1939 | British company ICI develops commercial process for making polyethene. |
1941 | British chemists John Whinfield (1901–66) and J. Dickson develop Terylene (Dacron). |
1941 | German company IG Farbenindustrie produces polyurethane. |
1943 | US Dow Corning company produces silicone plastics. |
1947 | British chemists produce acrylic fibres. |
1953 | German chemist Karl Ziegler (1896–1973) discovers catalyst for making high-density polyethene. |
1954 | Italian chemist Giulio Natta (1903–79) develops industrial process for making high-density polyethene (using Ziegler catalyst). |
1989 | Italian company Ferruzzi produces biodegradable plastic (based on starch). |