Access to Hydroxy‐Functionalized Polypropylene through Coordination Polymerization

Abstract

Preparation of polyethylenes containing hydroxy groups has been already industrialized through radical copolymerization under harsh conditions followed by alcoholysis. By contrast, hydroxy‐functionalized polypropylene has proven a rather challenging goal in polymer science. Propylene can't be polymerized through a radical mechanism, and its coordination copolymerization with polar monomers is frustrated by catalyst poisoning. Herein, we report a new strategy to reach this target. The coordination polymerization of allenes by rare‐earth‐metal precursors affords pure 1,2‐regulated polyallenes, which are facilely transformed into poly(allyl alcohol) analogues by subsequent hydroboration/oxidation. Strikingly, the copolymerization of allenes and propylene gives unprecedented hydroxy‐functionalized polypropylene after post‐polymerization modification. Mechanistic elucidation by DFT simulation suggests kinetic rather than thermodynamic control.

Study on synthesis and characterization of a novel pyridine imide ligated rare earth metal complex C28H51N2Ln (THF)n(CH2 SiMe3)3 (Ln = Sc, Y) and its catalytic performance in polymerization of isoprene

“…Here we simply synthesized the pyridine imine rare earth trialkyl Figures (2,3) by using the isofold trialkyl scandium complex Sc(THF) 2.5 (CH 2 SiMe 3 ) 3 and the trialkyl Yttrium complex Y(THF) 2.5 (CH 2 SiMe 3 ) 3 with [1] the pyridine imine derivative ligand (1: C 28 H 51 N 2 Sc(THF)(CH 2 SiMe 3 ) 3 ; 2: C 28 H 51 N 2 Y(THF) 0.625 (CH 2 SiMe 3 ) 3 . The catalyst can catalyze the polymerization of isoprene with high activity, and the microstructure of the obtained polymer is mainly CIS-1,4 whose molecular weight distribution is about 1.5.…”

“…The monomers were thoroughly dehydrated by using calcium hydride. (E)-N-1-(pyridin-2-yl)ethan-(2,6diisopropylphenyl)-1-imine were purchased from Aldrich [3] . Figure 1 shows the synthetic route of Complex 1 and 2.…”

“…The synthesis of Complex 1: In the glove box, Sc(THF) 2.5 (CH 2 SiMe 3 ) 3 (1.11 mmol) was prepared in a 75 mL [4] single-mouth flask at room temperature, followed by 10 mL n-hexane, which was dissolved and followed by an equal amount of (E)-N-1-(pyridin-2-yl)ethan-(2,6-diisopropylphenyl)-1-imine [3] . Reacting for 30 min, the red solution and orange solid were obtained, with total yields of 83.5%.…”

Visible Helicity Induction and Memory in Polyallene toward Circularly Polarized Luminescence, Helicity Discrimination, and Enantiomer Separation

“…The unsaturated double bonds along the backbone provide an additional probability for functionalization. Thus, helical polyallenes have received considerable attention [49–52] . We recently developed a family of Ni II ‐catalysts that promote the living polymerization of allene monomers with high helix‐sense selectivity and region selectivity, affording helical polyallenes in high yield with a controllable molar mass ( M n ) and narrow distribution ( M w / M n ) [49, 50] .…”