Synthesis of polyacetylene with sulfoxide functions

Abstract

Polyacetylene functionalized by sulfoxide groups was synthesized from poly(methyl vinyl sulfoxide) by the elimination of methanesulfenic acid under the action of a strong base at 20-50 °C.The thermal (150 °C) elimination of benzenesulfenic acid from poly(phenyl vinyl sulfoxide) is considered as a promising method for the synthesis of polyacetylene modi fied by sulfoxide functions. 1-6 In combination with other types of chemical modification, this method makes it pos sible to prepare acetylene copolymers with new surface, optical, and electronic properties. Since blocks of differ ent nature are thermodynamically incompatible, these co polymers can exhibit the microphase separation to form paracrystalline nanostructures in the solid state and the formation of Langmuir-Blodgett films or stable self or ganized micelle like nanoparticles in solutions. 6 These new varieties of polyacetylene seem challenging as anti static additives, homogenizing agents for polymeric mix tures, optoelectronic materials, sensors, switches, mo lecular conductors, and nanoelectrinic devices. 6 In this work, we present the results of studying new routes for the synthesis of functionalized polyacetylene from poly(methyl vinyl sulfoxide) (PMSO, 1) by a base under mild conditions at room temperature or on weak heating.We found that polyacetylene functionalized by sulf oxide groups (2) is readily formed from PMSO 1 via the partial elimination of methanesulfenic acid under the ac tion of a strong base at 20-50 °C.The soluble precursor of functionalized polyacetylene is PMSO 1. The latter was synthesized by the oxidation of poly(methyl vinyl sulfide) (PMS) with 30% hydrogen per oxide (equimolar amount of H 2 О 2 based on the PMS unit, acetone-benzene (9 : 1) mixture, 60 °C, 12 h). The oxidation proceeds only to the sulfide sulfur, does not involve the main chain, and induces no destruction of macromolecules, because no decrease in the molecular weight (MW) of the modified product was observed (MW of the sulfide polymer is 15000, and MW of the sulfoxide polymer is 16300).The physicochemical properties of the starting and oxidized polymers differ strongly: their consistence (resin and power) and solubility in water change (the sulfide polymers are not dissolved in water, while the sulfoxide polymers are highly water soluble).The structure of the modified polymers was found by analysis of the IR and 1 H NMR spectra.The IR spectrum of the oxidized polymer exhibits a very strong band of stretching vibrations of the S=O bond at 1030 cm -1 ; absorption bands at 1290 cm -1 and 1120 cm -1 are attributed to vibrations of the SO 2 bonds, and the non oxidized sulfide C-S bonds appear as a weak band at 680 cm -1 . 7, 8 The 1 H NMR spectra of PMSO (DMSO d 6 ) contain signals of Me groups of three types: the sulfide type at 1.89 ppm, sulfoxide at 2.07 ppm, and sulfone at 2.39 ppm; in addition, the spectrum contains a broad signal at 3.04 ppm corresponding to protons of the CH and CH 2 groups of the polymeric chain. According to the NMR spectroscopic data, under...

Modified copolymers of bifunctional vinyl ethers with methyl vinyl sulfide as active matrices of solid superbases

“…Under these condi tions, elimination of the side sulfoxide groups and forma tion of polyacetylene blocks, earlier observed in the reac tion of poly MVS with KOH methanol solution, 25 can be avoided.…”

Synthesis of Precisely Structured Olefin Copolymers by Phenylseleno Oxidation Elimination

“…On the contrary, there are some articles that report the oxidation elimination of sulfurcontaining polymers in order to prepare polyolefin and the conditions of oxidation elimination of the polymer are very complicated and the efficiency is relatively low. [22][23][24][25] Using features that the elimination efficiency of phenylseleno group is close to 100%, therefore, it is promising for developing various functional materials containing C-C double bonds under mild conditions.…”