A Comprehensive Analysis of the Thermal Elimination Reaction in a Poly(p-phenylene vinylene) Precursor

Abstract

Sulfonium precursor routes are the most popular synthetic routes to light-emitting poly(p-phenylene vinylene) (PPV) thin films. These routes involve a high-temperature solid-state thermal elimination reaction which yields PPV from its water-soluble precursor. The quality of PPV and hence its ultimate properties have a strong dependence on the polymerization parameters and thermal elimination conditions. The elimination reaction remains less understood. In this report, we have qualitatively and quantitatively analyzed the thermal elimination reaction using TGA, DSC, MTGA, TG-IR and transmission IR. The qualitative analysis focuses on identification of the underlying reactions and establishing the reaction sequence and reaction mechanisms. The quantitative analysis, on the other hand, focuses on the determination of the kinetic parameters of these reactions. The effect of heating rate and reaction environment on the luminescent properties of PPV have also been investigated.

Influence from Thermal Elimination Temperature of Precursor Polymer and Film‐forming Methods on the Photophysics of the Poly(2,5‐didodecyloxy‐p‐phenylenevinylene)

“…17,18 Thus, here we present our preparation of a poly-(2,5-didodecyloxy-p-phenylenevinylene) sulfonium bromide precursor polymer with a modified method compared to the literature, and the systematical investigation into the relationship between the properties of the organicsolvent-soluble PPV and the thermal elimination temperature. The thermal elimination condition had been tracked in several other PPV systems [17][18][19][20] by some in-situ techniques, such as FTIR, UV-vis, TGA, etc., directly in film or in solution where the reaction took place. These in-situ techniques gave clear pictures of the gradual elimination of sulfonium groups and the formation of PPV.…”

An IR study of poly-1,4-phenylenevinylene (PPV), the 2,5-dimethoxy derivative [(MeO)2-PPV], and their corresponding xanthate precursor polymers and monomers

“…While several workers have reported the principal infrared (IR) bands for PPV [3,[12][13][14][15][16][17][18][19], only one has proposed a detailed assignment of its characteristic absorptions throughout the midinfrared region (4000-400 cm −1 ) [3]. By contrast, no such in-depth analysis has been attempted for its dimethoxy analog [12,20,21].…”

Influence from the sulfonate group () on the conversion process and emission efficiency of poly(p-phenylene vinylene)

“…In order to perform this process, shown schematically in Fig. 1, the PTHT film is usually treated at 230 1C for several hours ($ 6 h) under vacuum, whereby tetrahydrothiophene groups, HCl and water are eliminated [5][6][7][8]. With a thermal treatment at such high temperatures, structural defects are created, affecting negatively the luminescence properties [9].…”