Polymerization mechanism study of poly(4-methyl-1, 3-pentadiene) and poly(4-methyl-1-pentene) prepared by using rac-[CH2(3-tert-butyl-1-indenyl)2]ZrCl2/13C enriched methylaluminoxane. (September 2017)

• Record Type: Journal Article
• Authors: Pragliola, Stefania; Botta, Antonio; Longo, Pasquale
• Is Part Of: European polymer journal. Volume 94(2017)
• Page Start: 332
• Page End: 339
• Publication Date: 2017-09
• Subjects: Coordination polymerization -- NMR Analysis -- Metallocenes -- Poly(4-methyl-1, 3-pentadiene) -- Poly(4-methyl-1-pentene); Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2017.07.024
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Polymerization of (4-methyl-1, 3-pentadiene) by a zirconocene/ 13 C enriched MAO catalyst. Polymerization Mechanism of (4-methyl-1, 3-pentadiene) and (4-methyl-1-pentene). First insertion in the polymerization of (4-methyl-1, 3-pentadiene). First insertion in the polymerization of (4-methyl-1-pentene). Abstract: 13 C NMR analysis of poly(4-methyl-1, 3-pentadiene) (poly(4-MPD)) obtained by using the C2 symmetric zirconocene based catalytic system: rac -[CH2 (3- tert -butyl-1-indenyl)2 ]ZrCl2 (1 )/ 13 C enriched methylaluminoxane (MAO) shows strong differences between the microstructure of the first inserted monomer unit and the in-chain inserted ones. The first insertion step results regiospecific, but not stereospecific, while the propagation step is regio- and stereoselective producing 1, 2 syndiotactic poly(4-MPD). This feature is justified by assuming a "chain end" controlled mechanism working for the propagation step of polymerization. 13 C NMR analysis of isotactic poly(4-methyl-1-pentene) (poly(4-MP)) obtained by using the same catalytic system shows that the first monomer insertion is partially enantioselective.