Kinetics of the reaction between alkaline sulfides and aryl dichlorides — model study on 4-chloro- and 4,4′-dichlorobenzophenones

✍ Scribed by Lotfi Hedhli; Christelle Lesclingant; Alain Fradet; Ernest Maréchal

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 790 KB
• Volume: 198
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1997.021980101

✦ Synopsis

Abstract

The kinetics of the reaction between alkaline sulfides and halogenated aromatic monomers was studied using lithium sulfide and 4‐chlorobenzophenone (1a) and 4,4′‐dichlorobenzophenone (1b) as models. The release of H~2~S from reaction medium and the possible formation of a compound between sulfide and N‐methyl‐2‐pyrrolidone (NMP) during the preliminary dehydration step are key steps of the reaction. The reaction proceeds following two successive kinetic regimes: a first one where rapid second‐order reactions of sulfide and thiolate with 1a or 1b take place, and a second one where the slow release of sulfide from the compound formed during dehydration is rate determining and therefore governs the molecular weight of final polymer. A good agreement was found between theoretical curves calculated from this kinetic scheme and experimental data, indicating a polymerization mechanism based on an S~N~Ar reaction mechanism.