The initial conditions for PEO modification involved the use of benzoic acid (0.5 mmol), PEO 6K (10 mmol based on repeat units), TBHP (1.0 mmol), and TBAI (0.1 mmol) in ethyl acetate (2 mL) at 80 ℃ (Table , entry 1). The reaction resulted in the quantitative attachment of benzoic acid to the PEO chain, indicating 5% functionalization of repeating units.