Polyketones are a family of high-performance thermoplastic polymers. The highly polar ketone groups in the polymer backbone of these materials gives rise to a strong attraction between polymer chains, giving rise to a high enough melting point (255 degrees celsius for Carilon), as well as improved solvent resistance and good mechanical properties. Unlike many other engineering plastics, aliphatic polyketones such as Royal Dutch/Shell's Carilon (where "R" in the diagram is an ethyl group) are relatively easy to synthesize and can be derived from inexpensive monomers. Carilon is made with a palladium(II) catalyst from ethylene and carbon monoxide). A small fraction of the ethylene is generally replaced with propylene to reduce the melting point somewhat. Wikipedia does not have an article with this exact name. ... A thermoplastic is a plastic that softens when heated and hardens again when cooled. ... A ketone is either the functional group characterized by a carbonyl group linked to two other carbon atoms or a compound that contains this functional group. ... The degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701–1744), who first proposed a similar system in 1742. ... A solvent is a liquid that dissolves a solid, liquid, or gaseous solute, resulting in a solution. ... A Shell petrol station sign in the UK A Shell gas station in the US The Royal Dutch/Shell Group of Companies (called Shell Oil in North America) is a major oil company, one of the top four oil companies in the world (along with BP, ExxonMobil, and Total). ... Ethyl is a two-carbon substituent in organic chemistry. ... In chemistry, a monomer (from Greek mono one and meros part) is a small molecule that may become chemically bonded to other monomers to form a polymer. ... This article describes the chemical element palladium. ... A catalyst (Greek: καταλύτης, catalytis) is a substance that accelerates the rate of a chemical reaction, at some temperature, but without itself being transformed or consumed by the reaction (see also catalysis). ... Ethylene or ethene is the simplest alkene hydrocarbon, consisting of two carbon atoms and four hydrogens. ... Carbon monoxide, chemical formula CO, is a colourless, odourless, flammable and highly toxic gas. ... Propylene, also known by its IUPAC name propene, is an organic compound having the chemical formula C3H6. ...

Silicone polymers were originally thought to have an analogous structure: replacing carbon atoms with silicon in the diagram above would change each ketone group into a silicone group. However, the familiar rubbery polymers were eventually found to contain siloxane groups instead. While the technical name was changed from "polysilicone" to "polysiloxane" shortly after this discovery was made, the common name of the polymer was already well-established in popular culture. Silicones, or polysiloxanes, are inorganic polymers consisting of a silicon-oxygen backbone (...-Si-O-Si-O-Si-O-...) with side groups attached to the silicon atoms. ... General Name, Symbol, Number Carbon, C, 6 Chemical series Nonmetals Group, Period, Block 14 (IVA), 2, p Density, Hardness 2267 kg/m3 0. ... General Name, Symbol, Number silicon, Si, 14 Series metalloid Group, Period, Block 14 (IVA), 3, p Density, Hardness 2330 kg/m3, 6. ... Siloxanes are a class of both organic and inorganic chemical compounds which consist entirely of silicon, oxygen, and an alkyl group. ...

External links

• Macrogalleria (http://www.pslc.ws/mactest/ketone.htm)
• A comprehensive directory of Polyketone (PK) resin suppliers, resins and processing information. (http://www.ides.com/plasticsweb/generics/PK.htm)