Anomalous swelling of a polystyrene matrix in organic solvents

Abstract

Swelling behavior of a commercial linear polystyrene, containing a small amount (<5% wt) of mineral oil, has been studied in three different classes of organic solvents (alkanes, alcohols and carboxylic acids) using both gravimetry and light microscopy. A comparison has been made with the results presented in earlier publications using a different linear polystyrene, without mineral oil. It is shown that the polystyrene containing mineral oil absorbs much higher amounts of solvent at lower temperatures then at higher temperatures. This anomalous behavior sharply contrasts with the polystyrene without mineral oil, which at lower temperatures absorbs much less solvent. Light microscopy of the diffusion layer reveals that in the polymer with mineral oil precipitation occurs during diffusion at low temperatures, but not at high temperatures. These results clearly show that the presence of small amounts of mineral oil (in quantities below the detection limit of FTIR) can cause significant changes in the sorption behavior of polymers. These results are interpreted by pre-existing nano-inhomogeneities, formed by the mineral oil, limited miscibility of oil in the polymer phase and high miscibility of solvent in the oil phase.

Diffusivity of alkanes in polystyrene

“…It is identical to the polystyrene used in previous studies [41,42], it has an average M w ca. 230,000 and average M n ca.…”

“…230,000 and average M n ca. 140,000 and its FTIR and 1 H-NMR spectra have been previously reported [42]. All the alkanes used in this work were bought from Sigma-Aldrich and had purities≥99%.…”

Influence of fiber content and chemical modifications on the transport properties of PP/jute commingled biocomposites

“…The thermodynamic parameters like activation energy of the diffusion process can be calculated from the diffusion data. The activation energy required for a process (here diffusion) can be calculated using the Arrhenius equation . where D is the diffusion coefficient, D o is a constant, E A is the activation energy, R is the gas constant, and T is the temperature in kelvin.…”

“…The thermodynamic parameters like activation energy of the diffusion process can be calculated from the diffusion data. The activation energy required for a process (here diffusion) can be calculated using the Arrhenius equation [35,36].…”

Swelling behavior of polymeric membranes to metalworking fluids

“…This type of analysis has already been realized to explain the swelling of PU and other polymers by solvents. 45 Similar data processing approaches are also proposed by Makrita et al, 46 or Bernardo et al 47 As described in section "Multiple Linear Regression," a range of descriptors for the MWF and the polymers were considered for inclusion as independent variables. Regarding HSP, the inclusion of d h in a model did not appear appropriate, as it is related to intermolecular interactions of the "hydrogen bonds" type, which should not be the dominant type of interactions between polymers and MWF.…”