Term: reaction injection moulding (RIM) https://doi.org/10.1351/goldbook.RT07628 Definition: reactive polymer processing that produces polymer monoliths by low-pressure injection and mixing of low-viscosity precursors into moulds. Note: Reaction injection moulding commonly uses two-component precursors that produce polymer networks after mixing. Related Terms: 1) reactive polymer processing (http://doi.org/10.1351/goldbook.RT07630). 2) viscosity (http://doi.org/10.1351/goldbook.V06627). Source: PAC, 2007, 79, 1801. 'Definitions of terms relating to the structure and processing of sols, gels, networks, and inorganic-organic hybrid materials (IUPAC Recommendations 2007)' on page 1824 (https://doi.org/10.1351/pac200779101801) Citation: 'reaction injection moulding (RIM)' 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.RT07628 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. 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.