2,2,4-Trimethyl-1,2-dihydroquinoline

2,2,4-Trimethyl-1,2-dihydroquinoline TMQ monomer.svg Monomer Structure of 2,2,4-Trimethyl-1,2-dihydroquinoline monomer 2,2,4-Trimethyl-1,2-dihydroquinoline 1,2-Dihydro-2,2,4-trimethylquinolineTMQ Antioxidant 8633 InChI=1S/C12H15N/c1-9-8-12(2,3)13-11-7-5-4-6-10(9)11/h4-8,13H,1-3H3 ZNRLMGFXSPUZNR-UHFFFAOYSA-N 294154 26780-96-1 8981 500-051-3 0553M374Q3 CC=1C=2C(NC(C)(C)C1)=CC=CC2 12 15 1 Solid 1.042 at 20°C 48 1 mg/L 07 09 Warning 412 273 2,2,4-Trimethyl-1,2-dihydroquinoline (usually abbreviated TMQ, known historically as Acetone-anil) is an aminic antioxidant commonly used as a stabiliser in rubbers and some plastics. Synthesis TMQ is produced by a poly-condensation reaction between aniline and acetone.2,4-DIMETHYLQUINOLINE Organic Syntheses 1948 28 49 10.15227/orgsyn.028.0049 free Structure left|thumb|The most common of several possible TMQ dimers. CAS 18121-94-3 The structure of TMQ is often represented by the monomer; however, the commercial material is typically a complex mixture of oligomers. Dimers, trimers, and tetramers are common, but high molecular weight versions are also available. ECHA includes nearly a dozen compounds in the registration for TMQ.Registration Dossier - ECHA https://echa.europa.eu/registration-dossier/-/registered-dossier/14768/1/1 echa.europa.eu 8 January 2025 Differences in composition between suppliers can affect performance, resulting a complex market. Applications TMQ is primarily used in rubber. It is a good antioxidant, but it gives low protection against flex cracking (fatigue) and is not effective as an antiozonant.https://onlinelibrary.wiley.com/doi/book/10.1002/14356007 Ullmann's Encyclopedia of Industrial Chemistry 2003-03-11 Wiley 978-3-527-30385-4 Wiley-VCH 1 en Rubber, 9. Chemicals and Additives 10.1002/14356007.a23_365.pub3 In tire formulations it is often paired with 6PPD. The high molecular weight of TMQ oligomers makes them non-volatile and therefore more effective as long term heat-protection agents. It also makes them less likely to leach out of the polymer. TMQ is relatively inert towards the cross-linking peroxides used to produce EPDM, or PEX and it therefore also sees use in these polymers.Ferradino Anthony G. Antioxidant Selection for Peroxide Cure Elastomer Applications Rubber Chemistry and Technology 1 July 2003 76 3 694–718 10.5254/1.3547763 See also Ethoxyquin - a structurally related antioxidant used as a preservative in foods References Category:Antioxidants Category:Quinolines