Term: petroleum pitch
https://doi.org/10.1351/goldbook.P04523

Definition:
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.

Note: The hydrogen @A00442@ (ratio of aromatic to total hydrogen atoms) varies between 0.3 and 0.6. The aliphatic hydrogen atoms are typically present in @A00228@ substituted on aromatic rings or as naphthenic hydrogen.

Related Terms:
1) aromaticity (http://doi.org/10.1351/goldbook.A00442).
2) alkyl groups (http://doi.org/10.1351/goldbook.A00228).
3) hydrocarbons (http://doi.org/10.1351/goldbook.H02889).
4) melting (http://doi.org/10.1351/goldbook.M03821).

Source: 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)

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. https://doi.org/10.1351/goldbook.P04523

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