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Elucidation of high ring‐opening polymerizability of methylated 1,6‐anhydro glucose
Authors:Dai Yoshida  Takashi Yoshida
Institution:Department of Bio and Environmental Chemistry, Kitami Institute of Technology, Koen‐cho, Kitami 090‐8507, Japan
Abstract:1,6‐Anhydro glucose was extracted from a wood tar that is a by‐product of charcoal manufacture. After methylation of the 1,6‐anhydro glucose, the starting monomer, 1,6‐anhydro‐2,3,4‐tri‐O‐methyl‐β‐D ‐glucopyranose (LGTME), was obtained. We found that LGTME had high ring‐opening polymerizability and polymerized under mild conditions. With BF3OEt2 catalyst under ordinary pressure and N2 atmosphere at 0 °C, LGTME gave high molecular weight of polymer with 1,6‐α stereoregularity in a high yield, even though benzylated 1,6‐anhydro glucose monomer (LGTBE) gave no polymers by the same polymerization conditions. The GPC profile showed two absorptions corresponding to equation image = 272 × 103 and equation image = 390 × 104 in the proportion of 4.5:1. Furthermore, under high vacuum condition at 0 °C, LGTME gave the corresponding polymer and the lower molecular weight increased to equation image = 364 × 103. To reveal the high polymerizability of LGTME, two‐step polymerization was performed. After the first stage of polymerization under ordinary pressure for 6 h at 0 °C, the second LGTME monomer was added to the polymerization mixture and then the polymerization was continued. It was found that the lower molecular weight of the resulting polymer increased to equation image = 394 × 103 and the yield was 78%. These results suggest that poly(LGTME) after the first‐stage polymerization has stable propagating end which has a restarting ability for the ring‐opening polymerization. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1013–1022, 2009
Keywords:biopolymers  high molecular weight  LGTME monomer  propagating end  renewable resources  ring‐opening polymerizability  ring‐opening polymerization  stability
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