Cationic polymerization of isoprene using CF3COOD/TiCl4 initiating system: A new view on the polymerization mechanism. (June 2018)

• Record Type: Journal Article
• Authors: Rozentsvet, Victor A.; Kozlov, Valery G.; Stotskaya, Olesya A.; Sablina, Nelly A.; Peruch, Frederic; Kostjuk, Sergey V.
• Is Part Of: European polymer journal. Volume 103(2018)
• Page Start: 11
• Page End: 20
• Publication Date: 2018-06
• Subjects: Cationic polymerization -- Isoprene -- Deuterium-containing initiator -- Mechanism of polymerization; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2018.03.039
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Kinetics of reaction do not depend on type of isotope of hydrogen in initiator. The initiation by deuterium ion occurs only at the beginning of the polymerization. The exact structures of head and end groups of polyisoprene were identified. Rate of polymerization strongly reduced due to deactivation of active centers. The mechanism of chain transfer to the double bond of polymer was proposed. Abstract: Cationic polymerization of isoprene with CF3 COOD/TiCl4 initiating system has been studied under different experimental conditions. It was shown that trans -1, 4 unit with different types of enchainment (regular head-to-tail and inverse head-to-head and tail-to tail) is a dominant structural unit of unsaturation part of polymer chain. The structure of head and end groups was established and mechanism of their formation was proposed. It was also demonstrated that initiation by deuterium ion occurs only at the very beginning of the polymerization followed by chain transfer to double bond of polymer with elimination of proton, which then initiates the growth of new chain. The synthesized polyisoprene is characterized by reduced unsaturation that is consistent with occurring of two side reactions: chain transfer to polymer and "polymerization" of olefinic double bonds of macromolecule.