Block copolymerization of allene derivatives with isocyanides by the coordination polymerization with ?-allylnickel catalyst

Abstract

A living block copolymerization of allene derivatives with 1‐phenylethyl isocyanide (3) using [(allyl)NiOCOCF3]2 (1) is described. After complete polymerization of allene monomers such as n‐octyloxyallene (2A) with 1, further addition of 3 to the reaction system yielded the corresponding block copolymers in high yield. For instance, a block copolymer (4A, Mn = 39,600, Mw/Mn = 1.20) was obtained in 96% yield by the addition of 3 ([3]/[1] = 250) to the living solution of poly(n‐octyloxyallene) (Mn = 14,400, Mw/Mn = 1.03) prepared by the polymerization of 2A in the ratio of [2A]/[1] = 90. The resulting copolymer was a brownish orange gum or a solid, depending on the length of each of the segments. The solubility of the block copolymers could be controlled by the allene components. The copolymer of 2A with 3 having appropriate length of segments was soluble in n‐hexane, while that of methoxyethoxyethoxyallene (2D) with 3 was soluble in methanol. © 1997 John Wiley & Sons, Inc.

Synthesis of PS-b-PPOA-b-PS triblock copolymer via sequential free radical polymerization and ATRP

“…The peaks located at 2.61 (“c,” four protons) and 1.75 (“e,” three protons) ppm were attributed to C H 3 C(CN)C H 2 C H 2 CO 2 moiety adjacent to azo group. The presence of Br‐containing ATRP initiating group was further verified by the distinct carbon resonance signals appearing at 21.4 (“k”) and 39.4 (“g”) ppm in C NMR spectrum [Fig. (B)].…”

“…Azo‐ATRP bifunctional initiator 1 was characterized by FT‐IR, 1 H NMR, C NMR, and elemental analysis in detail. Firstly, FT‐IR spectrum of compound 1 [Fig.…”

“… 1 H (A) and C (B) NMR spectra of bifunctional initiator 1 in CDCl 3 . [Color figure can be viewed at http://wileyonlinelibrary.com]…”

“…The chemical structure of resulting PPOA homopolymer was examined by GPC, FT‐IR, 1 H NMR, C NMR, and elemental analysis. GPC retention curve of the obtained homopolymer (Fig.…”

Synthesis of Helical Rod−Coil Multiblock Copolymers by Living Block Copolymerization of Isocyanide and 1,2-Diisocyanobenzene Using Arylnickel Initiators

“…The copolymerization would allow us to obtain copolymers that consist of highly contrasting polymer main chains, i.e., poly(quinoxaline-2,3-diyl)s as a highly rigid rod and poly( N -aryliminomethylene)s as a relatively flexible, yet tense, coil. Although “change-of-mechanism” copolymerizations of isocyanide with 1,3-butadienes, allenes, and glutamate N -carboxyanhydride have been reported using nickel initiators, the present copolymerization is likely to proceed with a single mechanism, i.e, insertion of the isocyano group into the M−C bond of the living polymer intermediates, despite the formation of two highly contrasting helical polymer backbones. In this report, we describe the copolymerization of isocyanide and 1,2-diisocyanobenzenes with organonickel initiators, which provides poly( N -substituted iminomethylene- b -quinoxaline-2,3-diyl)s featuring helical structures for both blocks.…”