Multibranched star-shaped polyethers

摘要

Synthesis of multibranched star-shaped polyethers having poly(ethylene oxide)s (PEO) arms is described. The novel method of preparing these multibranched macromolecules consists in reaction of the -OH ended oligomers with dicyclic compounds; e.g. monoalkyl ethers of poly(ethylene oxide) with diepoxides in the presence of a basic catalyst, converting a part of the similar toOH groups into similar toO(sigma) end groups (alkoxide anions). Analysis of the structure of these macromolecules was mostly based on H-1 NMR, MALDI-TOF, and SEC with triple detection. The absolute values of M-w (LS), M-w/M-n and [eta] are given, indicating formation of macromolecules of high molar mass and highly branched. The number of branches was estimated by several methods, including comparison of the Mark-Houwink (M-H) dependencies of the obtained products with the M-H dependence for PEO stars with exactly known number of arms. The final stars were phosphorylated at the -OH ended branches. Almost exclusively monoesters of phosphoric acid were found in P-31 (H-1) NMR. [References: 23]