Syntheses of Well-Defined Functional Isotactic Polypropylenes via Efficient Copolymerization of Propylene with ω-Halo-α-alkenes by Post-metallocene Hafnium Catalyst

Abstract

Catalyzed by the (pyridylamido)hafnium/organoboron system, a series of halogen-functionalized isotactic polypropylenes were synthesized via the stereospecific copolymerization of propylene with ω-halo-α-alkenes. The (pyridylamido)hafnium/organoboron system has been proved to be a potent catalyst for propylene/ω-iodo-α-alkenes copolymerization, producing well-defined poly(propylene-coω-iodo-α-undecene)s with outstanding properties. The high molecular weight (M w > 100 kg mol −1 ) functional iPPs possessing abundant iodoalkene units (up to 11.7 mol %) and unimodal molecular weight distributions (M w /M n ≈ 2) could be easily obtained under mild conditions with excellent catalytic activity. High isotactic selectivity of monomers, including propylene and polar comonomer, was unexpectedly observed ([mmmm] > 99%). Moreover, based on the unique copolymerization process and the highly reactive sites on the copolymers, the halogen groups of the resultant copolymers could be easily transformed into other polar groups via click chemistry, and the new functional iPPs with high molecular weights and abundant polar groups could be efficiently obtained.

Supported Single-Site Organometallic Catalysts for the Synthesis of High-Performance Polyolefins

“…Especially in the case of group 4, these new catalysts and cocatalyst/activators have achieved great success in the production of advanced polyolefin materials [4]. The new systems are able to control product molecular weight, polydispersity, comonomer enchainment level and pattern, the tacticity of poly(a-olefins) [17,56,57], copolymerization of olefins with polar comonomers (group 10) [54,55,[58][59][60][61][62], and the catalytic synthesis of block copolymers by processes such as chain shuttling polymerization [63][64][65][66][67].…”

Copolymerization of 4-methyl-1-pentene with α,ω-alkenols

“…Polyethylene and polypropylene are the polyolefin resins with the largest commercial scale. It follows then that most researches on the synthesis of the functional polyolefin concern ethylene [4][5][6][7][8][9][10][11][12][13] and propylene [14][15][16][17][18] copolymerization. The investigation on the copolymerization of higher α-olefin with functional monomer was rather rare.…”

New air stable cationic methallyl Ni complexes bearing imidoyl-indazole carboxylate ligand: Synthesis, characterization and their reactivity towards ethylene

“…[4,5] There are several reports on catalytic systems that indicate that they are able to produce polyethylene with varying branching degrees. [6][7][8] To date it is not possible to have an absolute control of the branching size and degree using only ethylene as monomer. It is a challenge to have a catalyst that allows absolute control of the microstructure of the polyethylene produced having only methyl branches.…”