FREE VOLUME THEORY OF DIFFUSION INTO POLYMERS. PART 1. METHOD OF PREDICTING ACTIVATION ENERGIES OF DIFFUSION FOR GASES INTO ELASTOMERS. PART 2. DIFFUSION OF NON-IONIC DYES INTO SEMI-CRYSTALLINE POLY(ETHYLENE TEREPHTHALATE) FILMS. PART 3. RELATIONSHIP BETWEEN GLASS-TRANSITION AND DYEING-TRANSITION TEMPERATURES.

摘要

The validity of Fujita's free volume theory, applied to the diffusion of various penetrants into polymers, has been tested. This dissertation is divided into three parts. In Part I, the diffusion of five gases into nine amorphous polymers is examined. An equation is derived to predict, amongst other things, the activation energies of diffusion from the WLF universal constants A and B, the temperature of diffusion, the glass transition temperature T(,g) of the polymer, and a constant K depending on the penetrant. This equation and the theoretical approach on which it is based are shown to be satisfactory for a set of five simple gases, diffusing into a set of nine elastomers. It is expected that similar success will be obtained for any other simple, noninteracting penetrant gas of the type used here, when diffusing in any other amorphous elastomer which obeys the WLF equation with the universal values of the constants A and B. The correctness of this expectation remains to be demonstrated. In Part II, the theory is applied to the disperse dyeing of semi-crystalline Poly(ethylene terephthalate) fibers and film. Some modifications were made to the theory for this case. Several systems such as vapor-phase dyeing, aqueous and solvent dyeing are examined. The analysis of the data confirms the validity of certain aspects of the proposed, modified free volume theory. A number of interesting complications are revealed and the theory will require modification to accommodate these complications. Part III contains an extension of the modified theory to describe the transition temperature of dyeing, T(,d). A mathematical expression is deduced which makes it possible to predict the transition temperature of dyeing from K, T(,g) and a reference temperature T in any system which conforms to the basic assumptions inherent in the modified theory. The predictions agree very well with the experimental data for a two-component, vapor phase dyeing system.