Thermal Degradation of Plasticized Poly(<Emphasis Type="Italic">para</Emphasis>-Methoxystyrene) in Solid Films

The thermal effect on the stability of poly(para-methoxystyrene) in solid films was studied within a temperature range of temperature range of 298–363 K. The fluorescence spectrum of poly(para-methoxystyrene) was found to be mainly excimeric emission at room temperature. However, this emission is quenched at higher temperatures. Added terephthalate and phthalate plasticizers to poly(para-methoxystyrene) caused a quenching of the excimer emission and enhanced exciplex emission. Thermal heating of the solid films of the plasticized and non-plasticized polymer was accompanied by quenching of fluorescence emission at low temperature and brought about a change in the structure of the fluorescence spectrum at high temperatures. This may indicate that thermodestruction of these polymers starts from a random chain scission. In addition to that the presence of the plasticizer in the polymer backbone was found to accelerate thermal degradation of the polymer. This was proved by the infrared spectra of the heated and unheated plasticized solid films of poly(para-methoxystyrene). The binding energy or excimer formation was calculated in solid film.