2019 Volume 76 Issue 4 Pages 276-287
A method for the precision synthesis of hetero-telechelic poly(ethylene glycol) (PEG)s with a carboxyl group at the alpha-terminus was studied. Hydroxypivalic acid (HPA) that contains both a hydroxyl group and a carboxyl group, was used as the starting compound. Anionic ring opening polymerization of ethylene oxide (EO) proceeded quantitatively by dropping a solution of HPA into potassium naphthalate THF solution, which induces highly dispersible initiators. In addition, it is indicated that macromonomers with a polymerizable group at the omega-terminus of PEG were synthesized quantitatively. And furthermore, a synthetic method to produce branched hetero PEGs with one carboxyl group at the alpha-terminus and two PEG chains were established by using a similar method. These quantitative synthetic methods of hetero PEGs possessing a carboxyl group at the alpha-terminus are promising for the creation of highly functionalized materials in the future.
