Non-isothermal elimination process in the solid state of n-alkyl-sulphinyl precursor polymers towards conjugated poly[2-(3′,7′-dimethyloctyloxy)-5-methoxy-1,4-phenylene vinylene] studied with MTDSC and TGA

The elimination process of n-alkyl-sulphinyl precursor polymers towards conjugated poly[2-(3′,7′-dimethyloctyloxy)-5-methoxy-1,4-phenylene vinylene], or OC1C10-PPV, was studied with modulated temperature differential scanning calorimetry (MTDSC) and thermogravimetric analysis (TGA), with a focus on the subsequent reactions of the elimination products. The latter reactions were monitored using the non-reversing heat flow and the heat capacity (Cp) measured in non-isothermal MTDSC experiments. The disproportionation reaction occurs in a temperature range between 85 and 135 °C and is seen as an increase in Cp. Water and elimination products released during the elimination reaction act as plasticizers and lower the Tg. TGA experiments show that the temperature, film thickness, and the eliminated group play an important role on the diffusion and evaporation of the elimination products. The elimination products can further decompose and interact with the conjugated system to form undesirable crosslinks (network formation) in a temperature range of 140-160 °C.