Thermodynamic modeling of the sorption of organic chemicals in thermoplastics and elastomers

Abstract

SYNOPSISThe amount of solute sorbed per unit weight of sorbent, qe, and the equilibrium solubility (partition) coefficient were measured using a gravimetric method for various types of organic chemicals in thermoplastics and elastomers. A thermodynamic model was derived to predict the activity-dependent partition coefficient and qe for a wide range of organic chemicals. The thermodynamic model produced a better fit to the measured qe values than did the Flory-Huggins equation. Partition coefficients and qe increased with increase in activity. For nonpolar compounds, qe increased logarithmically but decreased for polar compounds with an increase in the saturation organic chemical vapor concentration. Elastomers had 14-28 times greater qe values than did thermoplastics. A structure-activity relationship was found to accurately predict the partition coefficient for liphophilic organic chemicals at a specific activity.

Suitability of shredded tyres as a substitute for a landfill leachate collection medium

“…For landfill application, a tyre-chip layer thickness of 30 to 45 cm is recommended. Since the rate of organic compound sorption is a function of the diffusion coefficient and not the surface area (Glaza & Park 1992, Park & Bontoux 1993, tyre-chip size does not play a significant role. Park et al (1996) and Kim et al (1997) claimed that the tyre-chip had almost the same sorption capacity as crumb rubber if the fraction of steel belts, textiles, and fabrics in tyre-chips are excluded from the weight of tyre-chips.…”

Permeation of gasoline through DI pipe gaskets in water mains

“…Comparison of two methods for estimating the susceptibility of gasket materials to permeation. Maximum mass sorbed by polymers has been used to correlate with the permeation properties of polymers (Altinkaya et al, 2006; Park & Bontoux, 1993; Berens, 1985). Sorption weight gain and sorption rate (Table 1) were plotted as a function of total BTEX permeation rates (Table 3) as shown in Figure 6.…”

“…Permeation through polymer films or sheets can be complex (Park & Nibras, 1993; Flynn, 1983), and this study investigated thick gasket materials of irregular shapes. To estimate the diffusion coefficients of organic molecules in polymer films or sheets, both the half‐time method and the time‐lag method have been extensively used by polymer scientists.…”

Development of reactive artificial liner using recycled materials. 2. Chemical transport properties

“…In order to investigate how well the newly-developed artificial liner performed under extreme conditions, the samples were exposed to gasoline and mineral spirits. The gravimetric method, which employs weight measurements over time, was used to determine the transport parameters, such as partition coefficient (K), diffusion coefficient (D) and mass flux (F) (Glaza and Park, 1992; Kim et al, 1996; Park and Bontoux, 1991, 1993; Park and Nibras, 1993; Sangam and Rowe, 2005). As this method measures weight gain, the determined values are for the mixture of chemicals present in gasoline and mineral spirits (Al Zubaidy et al, 2013; Park and Nibras, 1993).…”