Abstract
This study explores multiple ways to functionalize poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and investigates the properties of the functionalized PPO. First, brominated PPO is prepared by atom transfer radical reaction and Wohl-Ziegler reaction. A new bromination method, radical and atom transfer halogenation (RATH), and its reaction mechanism has been demonsatrted. Compared to the conventional bromination methods, RATH can be performed at lower temperatures with less solvent restriction. Then, crosslinkable thermalplastic polymers, PPO-TEMPO and PPO-MAM, have been synthesized through bromination of PPO followed by atom transfer radical addition and nucleophilic substitution reaction, respectively. Structural and thermal analysis are carried out with FTIR, NMR, DSC and TGA. PPO-TEMPO could serve as a macroinitiator for nitroxide-mediated polymerization. Moreover, PPO-TEMPO and PPO-MAM are casted into films and thermally crosslinked to form crosslinked membranes with high gel fractions. The cured membranes exhibit excellent thermal properties, mechanical properties and solvent resistance as well as film formability.