Synthesis of Hyperbranched Polysaccharide by Thermally Induced Cationic Polymerization of 1,6‐Anhydrohexopyranose

Abstract

AbstractThe thermally induced cationic polymerizations of 1,6‐anhydro‐β‐D‐glucopyranose (1a), 1,6‐anhydro‐β‐D‐mannopyranose (1b) and 1,6‐anhydro‐β‐D‐galactopyranose (1c) as a latent cyclic AB4‐type monomer were carried out using (S‐2‐butenyl)tetramethylenesulfonium hexafluoroantimonate (2) as an initiator. The solution polymerization in propylene carbonate proceeded without gelation to produce the water‐soluble hyperbranched polysaccharides (3a‐c) with controlled molecular weights and narrow polydispersities. The degree of branching (DB), estimated by the methylation analysis of 3a‐c, was in the range of 0.38 – 0.49. The thermally induced cationic polymerization of 1a‐c using 2 is a facile method leading to a hyperbranched polysaccharide with a high DB value.