Abstract
A model is presented for diffusion-controlled sorption in polymer powders consisting of uniform spherical particles. Gravimetric sorption-rate data for vinyl chloride in PVC powders are found to obey this Fickian model for certain types of samples over limited ranges of vinyl chloride pressure increment or temperature. Superficially similar deviations from the model are caused by particle non-uniformity and by the onset of a relaxation-controlled transport mode. These two causes can be distinguished by appropriate choice of sample type and experimental conditions. A simple modification of the model satisfactorily accounts for the effect of particle non-uniformity upon sorption kinetics for conditions under which transport is diffusion-controlled. The use of powder samples in vapoursorption experiments seems to afford several advantages over conventional film specimens, including more convenient measurement of the very low diffusivities characteristic of the glassy state, and more definitive separation of the contributions of diffusion and relaxation processes to the overall transport mechanism.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
