Polymerization Behavior of Xanthate-Containing Monomers toward PPV Precursor Polymers:  Study of the Elimination Behavior of Precursor Polymers and Oligomers with in-Situ FT-IR and UV−Vis Analytical Techniques

Abstract

We have prepared two xanthate precursor polymers (6) and one sulfinyl precursor oligomer (7). In this way the polymerization behavior of three xanthate-containing monomers (3, 4, and 5) was studied. The chemical modifications on the monomer stage allowed to evaluate the outcome of the polymerization in relation to the chemical structure of the monomer. Polymerizations were performed in dry THF at different temperatures. The thermal conversion to the conjugated PPV structure, as well as its stability, was studied with different analytical techniques such as in-situ FT-IR spectroscopy, in-situ UV-vis spectroscopy, thermogravimetric analysis (TGA), and direct insert probe mass spectroscopy (DIP-MS). By combining the information obtained from these techniques, we were able to obtain a very detailed picture about the elimination process. These measurements also confirmed the formation of cis double bonds in xanthate precursor polymers on conversion. However, subsequent cis-trans isomerization in the end leads toward an all-trans-PPV polymer.

Facile Synthesis of Well-Defined MDMO-PPV Containing (Tri)Block—Copolymers via Controlled Radical Polymerization and CuAAC Conjugation

“…In order to target such applications, controlled polymerization methodologies need to be developed to reach a precision polymer design of these materials and to make them available for combination with other types of materials. Significant research has been performed towards the synthesis of PPVs, resulting in the indirect or so-called "precursor" route as the most established and reliable synthetic pathway [10][11][12][13][14][15][16][17][18][19][20][21]. The general polymerization mechanism proceeds via a self-initiating p-quinodimethane moiety, which is formed upon the 1,6-base elimination of a premonomer that then spontaneously polymerizes to form a precursor polymer [16,22,23].…”

“…Consequently, high conversions are easily reached within seconds to a few minutes enabling very fast polymerizations [24][25][26][27]. In a second step, elimination of the side group takes place, resulting in the desired conjugated polymer [15,23]. Over the last decades, different precursor routes were developed, for which the most important ones are the Gilch [11], Wessling [10,12,13], Xanthate [14,15], Sulfinyl [16][17][18][19][20] and Dithiocarbamate (DTC) route [28,29].…”

“…In a second step, elimination of the side group takes place, resulting in the desired conjugated polymer [15,23]. Over the last decades, different precursor routes were developed, for which the most important ones are the Gilch [11], Wessling [10,12,13], Xanthate [14,15], Sulfinyl [16][17][18][19][20] and Dithiocarbamate (DTC) route [28,29]. The sulfinyl route differs from the other routes since it is the only route in which an unsymmetrical premonomer is used and in which active monomer formation and prepolymer elimination can be fully separated from each other.…”

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

“…15,16 However, all these methods required additional synthetic effort, while the properties of PPV could be simply controlled by changing thermal elimination condition of the precursor polymer. 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.…”

“…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.…”