AbstractSolubility and diffusivity have been determined for bis‐(2‐chloroethyl)sulfide in isotactic polypropylene at temperatures from 15 to 40°C and relative pressures from 0.34 to 1.00. While the solubility in films annealed above 90°C followed the normal variation with the amorphous content, the quenched film had a significantly lower amorphous volume fraction than determined from its density, 46 instead of 60. The diffusion behavior in the film was found to be invariably Fickian and not dependent on the amorphous volume fraction of the polymer between 0.34 and 0.46. The solubility was found to be independent of the temperature over the range 15–40°C, but dependent on the diffusant concentration. The isotherms were well represented by the Flory‐Huggins relation for crosslinked polymers, and values for the interaction constant and the average molecular weight between crystallites have been obtained. The value of the interaction constant, μ = 1.13, is an expression of the low affinity bis‐(2‐chloroethyl)sulfide has for polypropylene. The intrinsic diffusivity was only weakly dependent on the diffusant concentration. The results were found to be in agreement with Fujita's free‐volume theory. The apparent activation energy for the diffusion of bis(2‐chloroethyl)sulfide in isotactic polypropylene was found
展开▼
