Convenient Syntheses and Versatile Functionalizations of Isotactic Polypropylene Containing Plentiful Pendant Styrene Groups with High Efficiency

• Published in: Macromolecules 2015-04, Vol.48 (7), p.1991-1998
• Main Authors: Wang, Xiao-Yan, Wang, Yong-Xia, Li, Yue-Sheng, Pan, Li
• Format: Article
• Language: English
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/acs.macromol.5b00128

Reported herein is the excellent example of regio-/stereoselective coordination copolymerization of propylene with p-(3-butenyl)­styrene (BSt) which produces exclusively high molecular weight (M w > 50 × 103) isotactic polypropylenes (iPPs) with abundant ethenylbenzene (styrene) groups (>5 mol %) by use of non-metallocene catalyst. The current (pyridylamido)­Hf/[Ph3C]­[B­(C6F5)4]/Al i Bu3 system, which exhibits overwhelmingly favorable reactivity toward α-olefin over styrene moieties, effectively promoted the copolymerization of propylene with BSt under judiciously chosen reaction conditions, in which catalytic activity (1.35 kg polymer/(mmolHf h), molecular weight (M w = 102 × 103), styrene group content (8.31 mol %), and tacticity ([mmmm] > 99%) reached a satisfying level simultaneously for the first time. Side group functionalized iPPs were synthesized in an almost quantitative way via the UV-light-initiated thiol–ene click chemistry and iodine-catalyzed hydroalkylation reaction of the resultant propylene/BSt copolymer with commercially available materials, demonstrating that the propylene copolymers containing abundant pendant styrene groups are excellent reactive intermediates for the preparation of various functional iPP materials.