The structural change of amorphous region of poly (ethylene terephthalate) (PET) films stretched uniaxially or biaxially was investigated by means of dye-diffusion behavior. The detailed stretching methods and characteristics of samples, such as crystallinity, molecular orientation and trans-gauche contents were the same as reported previously. The diffusion coefficients of disperse dye, C. I. Disperse Blue 26, were measured in the temperature range from 80°C to boiling temperature (about 100°C). The results are summarized as follows, (1) The morphology of amorphous region of PET inferred from the diffusivity of dye varied with stretching methods, namely orientation mode of the films. (2) Dense network of amorphous chain showed large molecular flexibility was obtained by uniaxial stretching. (3) On the other hand, expanded network of amorphous chain was obtained by biaxially stretching. (4) The dye diffusion behavior of polymer film was found to be suitable for the investigation of the structure of amorphous region of polymer stretched by various methods.
The apparatus of mechanochemical turbine in the mechanical shape and materials similar to those designed by A. Katchalsky was constructed. The experiment on the driving of mechanochemical turbine was performed to make clear some obscure points in Katchalsky's paper such as proper condition of crosslinking treatment of collagen film, theoretically induced revolution number and situation of turning. The following results were obtained; 1) crosslinking of collagen film with 2% formaldehyde aqueous solution and 10M LiBr aqueous solution as a contracting liquid were found to be suitable, 2) the equation of the calculated revolution number using the mechanochemical diagram was induced, 3) this turbine could not be turned continuously for a long period of time, but continuous several turnings were gained temporarily, and it was found that the observed revolution number was 2.5 sec-1 and the power was 26.5mW closed to the figure of 30mW obtained by Katchalsky. The results indicate that the induced equation of revolution number is valid and the power of 26.5mW would be acceptable.
The diffusion coefficient of phenol in polyester films was estimated at various concentrations and temperatures in order to elucidate a role of carriers in dyeing process of polymer. The diffusion coefficient of phenol in the amorphous region of polymer increased with increasing both concentration and temperature. This suggests that the sorbed phenol accelerates the segmental motion of the polymer chain. At the same time, dynamic moduli of two kinds of films were measured in phenol solutions at various temperatures and the dynamic moduli in the amorphous region EA' was calculated assuming the phenol was sorbed only in the amorphous region of polymer. Linear relationship was generally obtained between the EA' and the diffusion coefficients in amorphous region DA(c)in high concentration region of phenol. However, EA' deviated slightly from linear relation in low concentration region, which was attributed to the internal fine structure of each sample.
In heterogeneous system, the alkali saponification reaction of cellulose triacetate (CTA) membrane in the mixture of ethanol and water advanced with sharp moving boundary of reacted layer with a linear relationship of the thickness with the reaction time as in the case of ethylene-vinyl acetate copolymer membrane. Sorption and diffusion of H2O and C2 H5 OH under the pervaporation with the reaction were examined, and results were obtained as follows. Experimental values of permeation rates of H2O and C2H5OH through a partially saponified membrane agreed with those calculated by assuming the membrane to be a lamination of two layers of cellulose and CTA. For the pervaporation with the reaction, an equation was obtained. Where F is over all permeation rates for water or ethanol, k is the moving rate of the boundary front, l is the membrane thickness before the reaction and Pcell and PCTA are permeability constants for cellulose and CTA membrane, respectively. Plots of 1/F vs. t showed linear relationships for ethanol and water, respectively. From the results, the permeation constants for H2O and C2H5OH under the heterogeneous reaction were obtained. Diffusivity of alkali ion in the cellulose membrane was found 120 times larger than that in CTA membrane. Summarizing these results, it was concluded that the alkali saponification reaction under pervaporation advanced with a controlling step of boundary reaction. An analogy may be found between the reaction and the Case II type diffusion.
The annealed polypropylene (PP) films of crystallinity Cx (0.55_??_0.59) have been dyed with three water-soluble disperse dyes at a selected dyeing temperature ranging from 75°C to 90°C. The thermodynamic parameters of dyeing were determined from the adsorption isotherms by assuming the effective internal volume of PP to be (1-Cx )/ρa, where ρa is the amorphous density of PP. The values of standard enthalpy change (-ΔH°) and entropy change (-ΔS°) of dyeing thus determined were found to be positive, and decreased as the hydrophobic nature of the dye increased. On the other hand, the standard affinity increased with increasing the hydrophobicity of dye. This finding supports the idea that the entropic interaction forces between polypropylene and disperse dyes play an important role in the dyeing process of PP.