Synthesis of 4μ-PS2PtBA2, 4μ-PtPtBA2, and 4μ-Pl2PS2 Star-Shaped Copolymers by Combination of Glaser Coupling with Living Anionic Polymerization and ATRP

A study was conducted to demonstrate the Glaser coupling in the presence of a simple system of pyridine/CuBr/N,N,N',N',N'-pentamethyldiethylenetriamine (PMDETA) to prepare the precursors with two initiating sites at junction point. 4μ-A2B2 star-shaped copolymers were obtained by the atom transfer radical polymerization (ATRP) mechanism. The precursor PS(4) or PI(4) with two active hydroxyl groups at junction point was obtained by the hydrolysis of protected groups in the THF/HCl aqueous solution system. The process was completed by analyzing the disappearance of the resonance signal of the methyne group proton (-OCH(CH3)O-) from 1H NMR spectra at 4.70 ppm. The recovered hydroxyl groups at junction point of PS(4) or PI(4) were esterified with 2-bromoisobutyryl bromide at 0 °C for 24.0 hours for macroinitiators PS(5) and PI(5) with two 2-bromoisobutyryl groups at the junction point.