Synthesis and thermal analysis of aromatic polyethers having phosphine oxide groups.

Abstract

Aromatic polyethers, polyether I and II were synthesized by the reaction of bis (4-fluorophenyl) phenylphosphine oxide (BFPO) with alkali salt of 2, 2-bis (4-hydroxyphenyl) propane and 4, 4′-dihydroxybiphenyl, respectively. The thermal properties of the polyethers were studied by differential scanning calorimetry (DSC) and thermogravimetry (TG). In order to establish the characteristics of the polymerization, the alkali metal was changed, along with other reaction conditions such as the temperature and the time were changed. It was found that the polymerization in dimethyl sulfoxide (DMSO) using potassium at 185°C gave polyether I and II having 0.64 and 0.48dl/g of inherent viscosity, respectively. X-ray diffractograms of those polyethers indicated typical halo patterns, suggesting that they were amorphous. The glass transition was observed in DSC measurements at 197°C for polyether I and 225°C for polyether II. TG measurements showed that polyether I and II started to decompose in nitrogen at 505°C and 535°C, respectively. The activation energies (E's) of thermal degradation were also determined using TG. The values of E's were 164 kJ/mol for polyether I and 217 kJ/mol for polyether II.