Showing papers in "Transactions of The Faraday Society in 1953"

Departures of the Elastic Behaviour of Rubbers in Simple Extension from the Kinetic Theory

Abstract: It is shown that the equilibrium stress-strain behaviour of highly swollen rubber vulcanizates in simple extension agrees with the predictions of the kinetic theory. The departures from these predictions which are found in dry or lightly swollen rubbers have been investigated and it is shown that they can be described in terms of a single parameter C 2. The magnitude of this parameter is large in dry rubbers and decreases to zero at high degrees of swelling; this decrease occurs linearly with decrease in the volume fraction of rubber. The value of C 2 is found to be independent of the nature of the rubber polymer, of the degree of vulcanization, and of the nature of the swelling liquid. The possible significance of this parameter is discussed in light of these observations.

Thermodynamic and spectroscopic properties of associated solutions. Part 3

Abstract: A statistical theory of associated solutions is developed, taking into account the two main effects of association, (a) evolution of heat, (b) decrease in the number of possible orientations of the associated molecules. The theory is first applied to the association of a solute molecule with the solvent, and then to alcohols. It predicts the experimental behaviour of " unhindered" alcohols, for which the association constant of monomers into dimers is lower than that of higher order complexes. The excess free energy and excess enthalpy, deduced from this model and from spectroscopic data, for the system, CH3OH + CCl4, are in agreement with Scatchard's experimental values, without introducing any arbitrary parameter.