| Abstract: | The effect of moisture on the glass transition temperature of poly(hydroxy methylene) was investigated by thermal analysis which entailed combinations of DTA and DSC with TGA techniques. As the moisture content increased, the glass transition temperature (Tg) decreased monotonically from a value (Tgo) of 134°C for the dry polymer toward a finite value (Tgt) of about 39°C. This response of Tg to an increase in the moisture content (w) was adequately represented by the general relationship Tg = (ΔTg)0 exp{–ln(ΔTg)0]w/τwl} + Tgl, recently developed for correlating Tg and moisture content of nylon 6 and and found generally applicable to hydrophilic polymers. With (ΔTg)0 = 95, τ = 0.555, and wl = 0.375, good agreement was found between experimental and calculated values for poly(hydroxy methylene). |
