Phosphonic acid functionalized polyethylene glycol and derivatives

This article describes the functionalization of polyethylene glycol, mono or bifunctional, and a nonionic surfactant by phosphonic acids without the need for protection of the functional group. The functionalization is performed in two steps, first an esterification by thioglycolic acid, secondly a radical addition of vinyl phosphonic acid on the thiol group. All products were obtained quantitatively and characterized by 1 H‐, 13 C‐, 31 P‐NMR spectroscopy techniques, MALDI, and step‐by‐step chemical titrations. Enhanced thermal properties were found while phosphonylating polyethylene glycol, particularly when the sulfur atom was oxidized into a sulfone group.