Synthesis, structures and thermal properties of new class epoxide-terminated telechelic poly(2,6-dimethyl-1,4-phenylene oxide)s

Dihydroxyl telechelic poly(2,6-dimethyl-1,4-phenylene oxide)s (1) with regiocontrolled end-group structures have been synthesized by oxidative polymerization of 2,6-dimethylphenol with various aromatic diols in the presence of CuBr/dibutylamine catalysts. The novel one- or two-armed telechelic derivatives based on aromatic diols as core and 1 as arms were subsequently epoxidized with epichlorohydrin and a series of new epoxidized poly(2,6-dimethyl-1,4-phenylene oxide)s (2) were accessible with number average molecular weight ranged from 3500 to 14,000. The end-group structures and regioselectivity of polymers were controlled by the CuBr/dibutylamine catalysts under different reaction conditions, and the structures and properties were studied by nuclear magnetic resonance spectroscopy, gel permeation chromatography, thermogravimetric analysis and differential scanning calorimetry. Upon heating in the presence of oxygen, the one-armed dihydroxyl telechelic polymer was converted via intermolecular coupling and redistribution reaction to the two-armed derivative with significant increase in its molecular weight and elimination of diol monomer. Treatment of dihydroxyl telechelic derivatives with epichlorohydrin and NaOH afforded the epoxide-terminated telechelic derivatives in 77-94% yields.