Abstract2,6‐Dimethoxyphenol was polymerized using Ag2O‐triethylamine complex as catalyst and a study made of the effect of the catalyst‐monomer ratio on the yield, molar mass and polydispersity of poly(oxy‐2,6‐dimethoxy‐1,4‐phenylene). The glass transition temperaturesTgwere measured with a computerized differential scanning calorimeter. The effect of the molar mass onTgof poly(oxy‐2,6‐dimethoxy‐1,4‐phenylene) is discussed. The equation,Tg=Tg, ∞−K/M v0,64, describes well the dependence ofTgon the viscosity‐average molar massMvfrom 1900 to 176000 g/mol. Some poly(oxy‐2,6‐dimethyl‐1,4‐phenylene) sampl