G. F. Myachina

2-Arylazo-1 -vinylpyrroles : Free-Radical Polymerization and Copolymerization

2-Arylazo-1-vinylpyrroles (a new group of azo dyes of the pyrrole series) are polymerized under heating (80°C) without initiators and in the presence of AIBN to form intensely colored paramagnetic and conducting polymers with a yield of 92%. By the example of the thermal copolymerization with 1-vinylpyrrolidone, it has been shown that 2-arylazo-1-vinylpyrroles may simultaneously play the roles of initiators and comonomers.

Sulfur-rich copolymers of sulfur with 5-vinylbicyclo[2.2.1]hept-2-ene and tricyclo[5.2.1.0 2.6]deca-3,8-diene as prospective cathode materials for lithium cells

Catalytic copolymerization of sulfur with 5-vinylbicyclo[2.2.1]hept-2-ene or tricyclo[5.2.1.0 2.6 ]deca-3,8-diene (sulfur:diene ratio=20:1) at 170 v °C in bulk or decalin in the presence of 1,4-diazabicyclo[2.2.2]octane or N,N,N,N-tetramethylethylenediamine in combination with CoCl 2 - 6H 2 O or Cu(acac) 2 occurs at two dienic double bonds to form partially cross-linked copolymers stable up to 200 v °C (DSC/TGA). Preliminary evaluation of the specific discharge capacity of cathodes made using the above copolymers in model lithium button cells gives 670-970 and 300-330 v mA - h - g m 1 in the 1st and 50th cycles, respectively.

ETHYNETHIOL-BASED POLYENEPOLYSULFIDES FROM ACETYLENE AND ELEMENTAL SULFUR: SYNTHESIS AND PROPERTIES

Ethynethiol-based polysulfide polymers [Cssize 2}H2S x ] (x = 1-6) have been synthesized by the reaction of sodium acetylides and elemental sulfur in liquid ammonia with the following hydrolysis of sodium ethynethiolates and spontaneous polymerization of ethynethiols thus formed. The polymers are brown powders (up to 87% sulfur content), possessing electroconducting (10−13–10−14 S · cm−1), paramagnetic (1018 spin · g−1) and redox properties. Application of the polymers as active cathode materials provides for a stable cycling of model lithium batteries. * Now Sion Power Corporation.

Sulfurization of polymers. 6. Poly(vinylene polysulfide), poly(thienothiophene), and related structures from polyacetylene and elemental sulfur

Polyacetylene obtained by the dehydrochlorination of polyvinyl chloride in the NaOH—DMSO system undergoes sulfurization with elemental sulfur at 120—300 °C to liberate hydrogen sulfide and to form electroconducting (0.7·10–12—5.8·10–15Sm nm–1) and paramagnetic (1.5·1017—1.7·1019sp g–1, g = 2.0035—2.0045, ΔH= 0.44—0.66 mT) dark powders with a metallic luster. Their IR spectra and comparison with the samples of sulfurized polyethylene show that sulfurized polyacetylene contains poly(vinylene polysulfide), poly(thienothiophene), and related structures. The polymers afford the cathode discharge capacity of lithium batteries up to 950 mA h g–1(in the first cycle) and stable cycling at a level of 500—300 mA h g–1(25 cycles).

Sulfurization of polymers

Polyethylene exhaustively sulfurized with elemental sulfur shows paramagnetic (spin concentration 2.7–9.7·1019 sp g−1,g=2.0041–2.0045, ΔH=0.53–0.62 mT) and redox properties, which was demonstrated by both voltammetric and chemical methods (sodium reduction in liquid ammonia). The high concentration of unpaired electrons, the character of the electrochemical activity, and the chemical properties are in agreement with the presence in the polymers of polyconjugated ladder polythiophene and parquet polynaphtho-thienothiophene structures along with polyene-polysulfide blocks. The use of the polymers under consideration as an active cathode material in lithium batteries enables their repeated cycling with a specific charge capacitance of 150–340 mA hg−1.

Nucleophilic addition to acetylenes in superbasic catalytic systems: XV. Vinylation of 2-hydroxymethylfuran

Abstract2-Hydroxymethylfuran reacted with acetylene in superbasic catalytic systems MOH-DMSO (M = Na, K) under mild temperature conditions (75–85°C, 1–2 h), yielding 80% of 2-vinyloxymethylfuran. The product, as well as acetaldehyde acetals derived therefrom, turned out to be promising as modifiers for electrolyte in lithium-sulfur rechargeable batteries.

Modification of polyvinyl chloride with Na(K) salts of 1,2,4-triazole and 1,2,3-benzotriazole

The possibility of polyvinyl chloride modification by nucleophilic substitution of chlorine with sodium and potassium salts of 1,2,4-triazole and 1,2,3-benzotriazole in dimethylformamide at 40-80°C was examined.

Sulfurization of polymers: 2. Polythienothiophene and related structures from polyethylene and elemental sulfur

Polyethylene is exhaustively sulfurized by elemental sulfur at 160–365 °C to release hydrogen sulfide and form black lustrous powders (sulfur content ≈80%) that possess electric conductivity (10−6–10−8 S cm−1 when doped with I2). Elemental analysis data, IR spectra, X-ray patterns, DSC-TGA. derivatographic data, electric conductivity, and mass spectrometric characteristics of the polymers synthesized suggest the presence of fused polythienothiophene and polynaphthothienothiophene blocks in the polymers.

SOME FEATURES OF THE REDUCTION OF POLY(METHYLENE SULFIDES) AND POLY(METHYLENE POLYSULFIDES)

Abstract The reductive destruction of poly(methylene sulfides) and poly(methylene polysulfides) in the system hydrazine hydrate - NaOH at 70–1 15°C involves cleavage of the C-S bond and the formation of sulfide, disulfide and trisulfide anions. Nitrogen and methane are main gaseous products of reduction. The reduction of C-S bonds in these polymers is proven by electrochemical methods.

New catalyst for the synthesis of 2-Phenyl-1,2,3-triazole

A new catalyst was developed for the synthesis of 2-phenyl-1,2,3-triazole: copper triflate Cu(OSO2CF3)2. The process of cyclization of glyoxal phenylosazone in the presence of Cu(OSO2CF3)2 was optimized that made it possible to increase the yield of the target product to 82%.