Radical Polymerization of Styrene in Liquid Sulfur Dioxide

Polymerization reaction of styrene in liquid sulfur dioxide was carried out with α, α\u27 azo-bis (isobutyronitrile) as the initiator. Polymerization temperatures selected were 40°, 50°, and 60℃. The polymer thereby obtained were analyzed as styrene polysulfone but it was found that, irrespective of the polymerization temperature or polymerization rate, the polymers had a unit composition consisting of 2 moles of styrene and 1 mole of sulfur dioxide. From such an experimental fact, it was considered better to assume that a complex consisting of 2 moles of styrene and 1 mole of sulfur dioxide had formed prior to the initiation of polymerization, rather than treating this as the copolymerization of styrene and sulfur dioxide, and a kinetic treatment was made of the radical polymerization reation of this complex. As a result, the velocity of total polymerization reaction, Rp, was given as constant×[initiator]^_0[styrene+1/2SO_2]_0. Activation energy of the total reaction calculated on the basis of such hypothesis was 14.7 kcal/mole

Effect of Added Solvents on the Radical Polymerization of Acrylonitrile in Liquid Sulfur Dioxide

Acrylonitrile was polymerized by aa\u27-azobisisobutyronitrile (AIBN) as an initiator at 50℃ in liquid sulfur dioxide mixed with an added solvent. The added solvents were cyclohexane, benzene, toluene, p-xylene, ethylbenzene, isopropylbenzene, p-cymene, chlorobenzene, benzonitrile and ethyl benozate, respectivelv. In each case, only poly-acrylonitrile was obtained and the formation of the polymer was independent on the solvent added. No acrylonitrile polysulfone was found in the reaction mixture. The added solvents showed no appreciable influence on the overall rate of polymerization (Rp) in the range of the experimental condition

On the Beckmann Rearrangement in Liquid Sulfur Dioxide. I : Synthesis of ε-Caprolactam

The formation of ε-caprolactam from cyclohexanone oxime by the Beckmann rearrangement in liquid sulfur dioxide has been studied. When sulfuric anhydride SO_3 was used as a rearrangement reagent and the process was carried out at 20℃, the reaction proceeded stoichiometrically between the oxime and sulfuric anhydride, which approved of the mechanism of the Beckmann rearrangement proposed by Kuhara and Chapman, yielding 93.6 per cent of ε-caprolactam as maximum. The preparative method of using a small amount of the reagent and being conducted at room temperature without stirring will enable the lactam industry more economical. Other reagents for the rearrangement were also examined

Syntheses of 2, 2\u27-Diamino-Biphenyl and Carbazole from Phenathrene

Preparations of 2, 2\u27-diamino-biphenyl and carbazole from phenanthrene were described. Diphenic acid, obtained by the oxidation of phenanthrene, was converted to 2, 2\u27-diaminobiphenyl through diphenic acid diamide in good yield. This diamine undergoes deamino-cyclization to carbazole. Some attempted rearrangements in non-aqueous solutions were tried ineffectively