Use of mercury porosimetry for characterization of poly(vinyl chloride) suspension grades with regard to particle type, particle heterogeneity, and surface area

The correction for polymer and mercury compressibility is essential to the use of mercury porosimetry for the evaluation of the porosity of poly(vinyl chloride) (PVC) suspension granules. The polymer compressibility, however, varies with the morphology type of the granules. The technique outlined in this paper allows the appropriate correction to be made without the need for the prior determination of the polymer compressibility. Bulk‐compressibility factors for the polymer samples are derived from the porosimetry data. Surface areas of PVC granules, as derived from porosimetry data using two fundamentally different techniques, are in error because of the presence of “ink‐bottle” shaped pores.