Synthesis of poly(dihalophenylene oxide)s by atom transfer radical rearrangement polymerization via Ce(IV)/Ce(III) complexes in solid state

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Poly(dihalophenylene oxide)s by solid-state thermal decomposition of (trihalophenolato) cerium complexes with either N-methyl imidazole or pyridine as neutral ligands were synthesized at different temperatures (80–250°C) and different time intervals (3–48 h) via atom transfer rearrangement radical polymerization. The complexes were characterized by FT-IR, DSC, SEM, mass spectroscopy, magnetic susceptibility and elemental analyses. Structural analyses of polymers were performed by 1H- and 13C-NMR, SEM and FT-IR spectroscopic analyses, T g by DSC and the molecular weights by viscometry. 2,4,6-Trichlorophenolate displayed a slightly higher selectivity in favor of 1,2-addition, whereas 1,2- and 1,4-additions took place at equal rates in the case of 2,4,6-tribromophenolate. Pyridine complexes decomposed at lower temperatures and had lower polymer yield than the N-methyl imidazole complexes. Among the synthesized polymers in solid state, the highest intrinsic viscosity value of 0.058 dl/g (M w = 7.15 × 104) was achieved only with Ce(TCP)3(Py)2 complexes. All the polymers having high T g values (178–189°C) were rigid.