Isothermal Elimination of n-Alkylsulfinyl OC1C10-PPV Precursor Polymers Studied with FT-IR, UV−Vis, and MTDSC: Kinetics of the Elimination Reaction

Abstract

The conversion of n-alkylsulfinyl OC1C10-PPV precursor polymers to the conjugated OC1C10-PPV polymer and the subsequent reactions of the elimination products in the solid state are studied in situ with FT-IR, UV−vis spectroscopy, and modulated temperature DSC (MTDSC). FT-IR and UV−vis spectroscopy allow monitoring the formation of double bonds in the conjugated system. The experimental activation energy of this conversion reaction is in good agreement with the value from theoretical modeling (101 kJ/mol). Quasi-isothermal MTDSC heat capacity measurements permit the characterization of the subsequent reaction steps of the elimination products (dimerization of sulfenic acid and disproportionation of thiosulfinate). The formation of water in the dimerization step and elimination products results in a positive reaction heat capacity (ΔrCp). This increase in heat capacity is slower than the formation of double bonds, which is attributed to the fact that the dimerization and disproportionation reactions behave ...