{"term":{"id":"04523","title":"petroleum pitch","longtitle":"IUPAC Gold Book - petroleum pitch","doi":"10.1351\/goldbook.P04523","code":"P04523","status":"current","definitions":[{"id":1,"text":"A residue from heat treatment and distillation of petroleum fractions. It is solid at room temperature, consists of a complex mixture of numerous predominantly aromatic and alkyl-substituted aromatic hydrocarbons, and exhibits a broad softening range instead of a defined melting temperature.","notes":{"1":"The hydrogen aromaticity (ratio of aromatic to total hydrogen atoms) varies between 0.3 and 0.6. The aliphatic hydrogen atoms are typically present in alkyl groups substituted on aromatic rings or as naphthenic hydrogen."},"links":[{"term":"alkyl groups","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/A00228"},{"term":"aromaticity","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/A00442"},{"term":"hydrocarbons","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/H02889"},{"term":"melting","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/M03821"}],"sources":["PAC, 1995, 67, 473. 'Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)' on page 499 (https:\/\/doi.org\/10.1351\/pac199567030473)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/P04523\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/P04523\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/P04523\/plain"},"citation":"Citation: 'petroleum pitch' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.P04523","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2026-05-09T01:52:59+00:00"}}