BLOCK COPOLYMERIZATION OF ALLENE DERIVATIVES WITH ISOCYANIDES BY THE COORDINATION POLYMERIZATION WITH PI-ALLYLNICKEL CATALYST

A living block copolymerization of allene derivatives with 1-phenyleth yl isocyanide (3) using [(allyl)NiOCOCF3](2) (1) is described. After c omplete polymerization of allene monomers such as n-octyloxyallene (2A ) with 1, further addition of 3 to the reaction system yielded the cor responding block copolymers in high yield. For instance, a block copol ymer (4A, M(n) = 39,600, M(w)/M(n) = 1.20) was obtained in 96% yield b y the addition of 3 ([3]/[1] = 250) to the living solution of poly(n-o ctyloxyallene) (M(n) = 14,400, M(w)/M(n) = 1.03) prepared by the polym erization 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 cont rolled by the allene components. The copolymer of 2A with 3 having app ropriate length of segments was soluble in n-hexane, while that of met hoxyethoxyethoxyallene (2D) with 3 was soluble in methanol. (C) 1997 J ohn Wiley & Sons, Inc.