The synthesis of some model allene molecules and the study of molecular interlocking in their melts. Part II. Thermodynamic and transport properties of tetraphenylallene–pyrene mixtures

Abstract

Excess volumes and viscosity–temperature parameters have been determined for binary mixtures of tetraphenylallene with pyrene. Addition of pyrene leads to a steep rise in excess volume, with a maximum at about 25 moles %. This can be correlated with a steep drop in the nominal activation energy for the temperature dependence of viscosity, which attains its lower limit for about the same compositions.

Both effects are discussed in terms of a breaking down of anti-crystalline clusters of interlocked molecules of tetraphenylallene resulting from the dilution of its melt with pyrene molecules.