Allylthioketone mediating radical polymerization of butyl acrylate. (16th August 2021)

• Record Type: Journal Article
• Authors: Zhong, Feng; Pan, Cai-Yuan
• Is Part Of: Polymer. Volume 229(2021)
• Publication Date: 2021-08-16
• Subjects: Allylthioketone -- Controlled radical polymerization -- Poly(butyl acrylate); Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2021.123972
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: By combination of high trapping radical efficiency of thioketone with resonance of allylic radicals, a novel mediated agent, 1, 3, 3-triphenylprop-2-ene-1-thione (TPPT) has been successfully synthesized. 1 H NMR method was used to trace the TPPT-mediated radical polymerization of butyl acrylate (BA) at 50 °C, we observed that the disappearance rates of BA, TPPT and initiator, dimethyl 2, 2′-azobis (2-methylpropionate) (AIBME) have the following order: BA > AIBME > TPPT, monomer conversion increases gradually with proceeding of the polymerization and approximately 84% of conversion was obtained within 24 h of the polymerization. The molecular weights of the obtained PBA are not varied obviously with the conversion, but the molecular weight distributions are narrow. The matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) studies reveal three polymerization mechanisms. The TPPT can efficiently capture the growing PBA radicals to form PBA-TPPT radicals, and this highly stable radicals are able to be cross-terminated by the growing PBA radicals or primary radicals to form the dormant chains. Although the reversed reaction of reaction 1 is very slow, the extension polymerization of the PBA can undergo to form block copolymers. The molecular weight of the formed PBA is influenced by the feed molar ratio of BA/TPPT and TPPT/AIBME. Graphical abstract: Image 1 Highlights: Allylthioketone mediating free radical polymerization. High efficiency of capturing propagating radicals to form highly stable chain radicals. First order kinetics of polymerization and narrow molecular weight distribution. Independence of molecular weights with monomer conversion.