Reaction of oligoalcohol with diepoxides: An easy, one-pot way to star-shaped, multibranched polymers. II. Poly(ethylene oxide) Stars - Synthesis and analysis by size exclusion chromatography triple-detection method

Starlike, highly branched (A(x)B(y)A(z)) macromolecules having from a few to 100 arms and molar masses up to 10(5) were prepared in three stages with the one-pot, arms-core-arms method (B-y stands for y molcules of former diepoxides introduced into the core). Oligoalcohols, at least partially converted into their alcoholate counterpart states, reacted with diepoxy compounds giving star-shaped, highly branched macromolecules. With the properly chosen conditions, complete conversion of both starting components was achieved. In this article homostars built with the first and second generation of poly(ethylene oxide) arms (A(x) and A(z), respectively) are described. The number of arms (f) was determined either by direct measurements of the number-average molcular weight (M-n) of the first and second stars (M-n of arms A(x) and A(z) is known) or by calculating f from branching indices g and g' determined from the radius of gyration and the limited viscosity number measured with size exclusion chromatography (SEC) triple detection with TriSEC software. For a few samples, M-n was measured with high-speed membrane osmometry. The progress of the stars' formation was monitored by H-1 NMR, SEC, and matrix-assisted laser desorption/ionization time-of-flight methods. Functionalization of the -OH end groups in the second generation of arms was observed by H-1 and/or P-31 NMR. (C) 2004 Wiley Periodicals, Inc.