VISCOSITY OF LIQUID SULFUR . A MECHANISTIC REINTERPRETATION

The viscosity of liquid sulfur above 160° is calculated assuming that molecular flow is the only flow mechanism. The calculation is based on the values of the degree of polymerization and the monomer concentration as applied to the recent theory of Fox and Allen. It is shown that the calculated viscosity is ca. 104 times greater than the experimental viscosity. The possibility of bond interchange and of chain-end interchange is introduced, but these mechanisms lead to an underestimated value of the viscosity. In spite of the current inability to calculate the viscosity of sulfur precisely on the basis of chemical reactions, it seems highly probable that the viscosity of liquid sulfur is most probably governed by some type of chemical interchange rather than molecular flow. © 1969, American Chemical Society. All rights reserved.