Sorption,desorption, resorption,redesorption, and diffusion of haloalkanes into polymeric blend of ethylene–propylene random copolymer and isotactic polypropylene

Molecular transport of haloalkanes into sheets of a polymeric blend of an ethylene–propylene random copolymer and isotactic polypropylene has been studied by a sorption gravimetric technique in the temperature interval of 25–70°C. For all liquids, equilibrium sorption, desorption, resorption, redesorption, and degree of penetrant overshoot have been influenced by the nature of the liquid and the temperature. Diffusion coefficients were calculated from the sorption–desorption kinetic curves using Fick's mathematical relations. The values of diffusion coefficients followed the Arrhenius-type behavior. The temperature-dependent sorption data were analyzed using the van't Hoff relation. The activation parameters for diffusion and heat of sorption data were discussed in terms of the molecular interactions between liquids and the polymer chain segments. The experimental and calculated results are discussed on the basis of the chemical nature of liquids. © 1995 John Wiley & Sons, Inc.     

Molecular transport of esters,aldehydes, aromatic liquids,and a ketone into fluoroelastomer membrane at 30, 40, and 50°C

Molecular transport of esters, aldehydes, substituted aromatic liquids, and a ketone through a fluoroelastomer (FC‐2120) membrane sample was studied at 30, 40, and 50°C. Sorption results were obtained by using a gravimetric method and concentration‐independent diffusion coefficients were calculated using Fick's diffusion equation. Permeability coefficients were calculated from sorption and diffusion data. Concentration profiles of the liquid penetrants were calculated by solving the Fick's equation under appropriate initial and boundary conditions and these plots are displayed to show the variations in liquid concentrations with reference to the nature of liquids chosen, membrane thickness, as well as the time of polymer immersion in the liquids. Arrhenius activation parameters were also estimated from a temperature dependence of diffusion and sorption coefficients. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 840–847, 2003     

A study of sorption/desorption and diffusion of substituted aromatic probe molecules into semi interpenetrating polymer network of polyurethane/polymethyl methacrylate

The sorption-desorption-resorption-redesorption experiments have been conducted to evaluate the transport behaviour of polyethylene glycol (PEG) based polyurethane/polymethyl methacrylate (PU/PMMA, 50/50) semi interpenetrating polymer network (SIPN) with aromatic probe molecules. Molecular migration depends on the nature of the organic solvent, membrane-solvent interaction, temperature, solubility parameter, molecular volume and free volume available within the polymer matrix. The transport parameters like sorption (S), diffusion (D) and permeation (P) coefficients have been calculated for IPN-aromatic probe molecule systems. Sorption and diffusion results measured at different temperatures viz. 20, 40 and 60 °C are found to follow Fickian mechanism. The liquid concentration profiles in the membranes during sorption and resorption processes have been simulated by solving Fick's diffusion equations and by using numerical method. Equilibrium swelling results have been used to measure the molecular mass between cross links, degree of cross linking and cross link density using Flory-Rehner theory. It is found that the mass uptake values decreased with increase in cross link density during polymer-solvent interactions. The estimated Arrhenius activation energy for diffusion (E_D) and permeation (E_P) are indicative of nature of liquid and their interaction with membrane. Thermodynamic parameters like change in entropy (ΔS) and enthalpy (ΔH) have been calculated using van't Hoffs equation. The rate of evaporation of liquids have been calculated for desorption and redesorption runs, and these results depend on volatility of solvents.     

Sorption/desorption,diffusion, and swelling characteristics of geomembranes in the presence of halo‐organic liquids

Sorption/desorption results of halogen‐containing liquids into high‐density polyethylene, linear low‐density polyethylene, very low‐density polyethylene, and polypropylene geomembranes are presented at 25, 50, and 70°C. Sorption results are obtained by a gravimetric method, and diffusion coefficients have been calculated by using Fick's equation from the initial linear portions of the sorption/desorption curves. Swelling of the geomembranes was studied from a measurement of the increase in volume, thickness, and diameter. From a temperature dependence of sorption and diffusion coefficients, the Arrhenius parameters have been calculated. Liquid concentration profiles have been computed using Fick's equation for the appropriate initial and boundary conditions. The results of this study may have relevance in selecting the suitable geomembrane for a specific application in hazardous waste chemical ponds and other similar situations.     

Sorption,Desorption, and Diffusion of Haloalkanes into Miscible Polymeric Blends of Ethylene-Propylene Random Copolymer and Isotactic Polypropylene

Molecular transport of haloalkanes into polymeric blend sheets of ethylene-propylene random copolymer and isotactic polypropylene, Santoprene, has been investigated gravimetrically in the temperature interval 25°-70°C. Equilibrium sorption, desorption, resorption, redesorption, and degree of penetrant overshoot were influenced by the type of haloalkane used and the experimental temperature. Diffusion coefficients have been computed for the sorption (S), desorption (D), resorption (RS), and redesorption (RD) runs. Temperature-dependent sorption and diffusion coefficients were analyzed using the Arrhenius relation. Santo-prene-haloalkane interactions have been discussed in terms of sorption, desorption, and diffusion coefficients.     

Sorption/desorption and diffusion kinetics of ketones and nitriles into fluoropolymer membranes

Analysis of sorption/desorption and diffusion kinetics of ketones and nitriles at 25, 44, and 60°C into three Du Pont's VITON fluoropolymer membranes loaded with different amounts of carbon black has been undertaken by use of a sorption/desorption technique. The transport results are affected by the percent loading of carbon blacks. Diffusion coefficients have been calculated from Fick's equation. These results show a decrease with increasing amount of carbon black. Experimental results have been analyzed by considering swelling of the membranes. Sorption/desorption results have been analyzed from a calculation of the concentration profiles, which are obtained from the analytical solution of Fick's equation. These results have been compared with a numerical solution based on the finite difference method. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 635–647, 1997     

Solvent Migration and Drying Phbnoubnon of Polymeric Blends of Ethylene-Propylbnb Random Copolymbr and Isotactic Polypropylbnb in the Prbsbncb of Monocyclic Aromatic Liquids at Tbwbraturbs Bbtukbn 25-70°C.

ABSTRACT

Solvent sorption and drying performance of engineering polymeric blends of ethylene–propylene random copolymer and isotactic polypropylene in the presence of aromatic liquid: has been studied in the temperature interval 25–70°C. The drying of the polymer is studied from the desorption and redesorption experiments. The present results indicate that the rate of solvent migration and the drying phenomenon is controlled by internal mass transfer of solvent molecules within the polymer matrix. A technique is developed to study the sorption (S) –desorption (D) – resorption (RS)–redesorption (RD) i.e., S–D–RS–RD of the polymer sheets. The S–D–RS–RD experiments are a convenient measure of knowing the continuous weight loss of the polymer during long–term solvent exposure.     

Sorption equilibria and diffusion of toluene,methanol, and cyclohexane in/through elastomers

Molecular transport of toluene, methanol, and cyclohexane and their mixtures in Chemraz 505 elastomer has been investigated using gravimetric techniques for short and long time exposure in these solvents. The sorption–desorption results have been used to calculate the diffusion coefficients by solving Fick's equation under appropriate boundary conditions. The dependence of sorption, desorption, diffusion, and permeation on temperature and composition changes was also studied. The results are discussed in terms of possible interactions between Chemraz 505 polymer and the solvent molecules. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43449.     

Experimental and simulation studies on molecular transport of substituted monocyclic aromatic liquids into fluoropolymer sheet membranes: Liquid structure–diffusion, –sorption,and –permeation relationships

The present study reports an investigation on the molecular transport of 10 monocyclic aromatic liquids (benzene, chlorobenzene, 1,2‐dichlorobenzene, bromobenzene, toluene, p‐xylene, trimethylbenzene, ethylbenzene, methoxybenzene, and ethoxybenzene) at 40 and 50°C through sheet polymeric membranes (FLS‐2650) using a sorption gravimetric technique. Diffusion and permeation coefficients of these liquids were calculated from the sorption data using Fick's diffusion equation. Sorption results were analyzed typically in the case of benzene and chlorobenzene to compute the concentration profiles at different depths along the thickness direction of the sheet membranes and at different time intervals by solving the Fick's equation under appropriate boundary conditions, based on the numerical simulation method developed in “C” language using a finite‐difference method. Transport results were analyzed to establish the relationships between the penetrating liquid structures with diffusion, permeation, and sorption data. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 991–996, 2004     

Molecular transport of alkanes through thermoplastic miscible blends of ethylene–propylene random copolymer and isotactic polypropylene

A new experimental protocol based on the measurements of sorption (S), desorption (D), resorption (RS), and redesorption (RD) has been used to study the molecular transport of aliphatic alkanes through the miscible blends of an ethylene–propylene random copolymer and an isotactic polypropylene over the temperature interval 25–70°C. Diffusion and activation parameters are evaluated and their dependencies on solvent size, shape, and nature are discussed. Estimated values of the molar mass between chain entanglements, kinetic rate constants, and overshoot index parameters have been influenced by the polymer–solvent interactions. The sorption–diffusion mechanism is found to be of anomalous type. © 1995 John Wiley & Sons, Inc.     

Effect of carbon black loading on fluoroelastomer–solvent interactions

An analysis of the molecular transport of organic liquids into fluoroelastomer membranes containing varying amounts of carbon black has been undertaken by the sorption–desorption gravimetric method. The variation in carbon black loading and temperature showed a significant effect on their transport characteristics. Diffusion coefficients were calculated from Fick's equation. Experimental sorption–desorption results were analyzed in terms of concentration profiles obtained from a solution of Fick's equation as well as by a numerical method based on the finite difference technique. Arrhenius activation parameters were estimated from the temperature-dependent diffusion and permeation data. The results of this study are discussed in terms of polymer–solvent interactions. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:815–825, 1998     

Molecular transport of aromatic hydrocarbons through lignin‐filled natural rubber composites

The diffusion and transport of organic solvents through lignin‐filled natural rubber composites have been studied in the temperature range 25–45°C. The diffusion of aromatic solvents through these samples were studied with special reference to the effect of filler concentration, penetrant size, and temperature. Transport coefficients such as diffusion, permeation, and sorption coefficients were estimated. The van't Hoff relationship was used to determine the thermodynamic parameters. The first order kinetic rate constant has been evaluated. A correlation between theoretical and experimental sorption results was evaluated. POLYM. COMPOS., 28:15–22, 2007. © 2007 Society of Plastics Engineers     

Sorption,diffusion, and swelling characteristics of sodium alginate and its blend membranes with poly(vinyl alcohol) in water–acetic acid mixtures

Sorption, diffusion, and swelling characteristics of sodium alginate and its blend membranes with poly(vinyl alcohol) were investigated for water–acetic acid mixtures by using a gravimetric method at 30, 40, and 50°C. The membranes were characterized by X‐ray diffraction and Fourier transform infrared techniques. Concentration‐independent diffusion coefficients were obtained by applying Fick's relationship before completion of equilibrium sorption. Permeation coefficients were calculated from sorption and diffusion coefficients. Concentration profiles of liquids were computed considering the sheet geometry for the membrane by solving Fick's equation under suitable boundary conditions. Arrhenius activation parameters were computed for the transport processes. Experimental results and calculated quantities were discussed to understand membrane–solvent interactions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1139–1150, 2004     

Diffusion and Sorption of Organic Liquids Through Polymer Membranes. IX. Bromobutyl Rubber,Chlorosulfonated Polyethylene,and Epichlorohydrin Versus Substituted Monocyclic Aromatic Liquids

Sorption and diffusion of four monocyclic aromatic liquids—namely, chlorobenzene, o-dichlorobenzene, bromobenzene, and nitrobenzene into bromobutyl rubber, chlorosulfonated polyethylene, and epichlorohydrin—have been investigated in the temperature interval of 25–60°C by using a gravimetric technique. The transport results have been analyzed by using the Fickian model of diffusion. The dependence of transport coefficients on the size and shape of the penetrant molecules has been discussed. Transport coefficients have not shown any systematic variation with the penetrant size, but the results are greatly influenced by the polymer-solvent interactions. The Arrhenius activation parameters have been estimated from a temperature dependence of sorption, diffusion, and permeation coefficients. The first-order kinetic rate constants have been obtained from the time-dependent sorption data. Enthalpy and entropy of sorption for the polymer-solvent systems have been studied. The molar mass between network crosslinks was calculated from the Flory-Rehner theory. Computed parameters and experimental results are used to discuss the transport mechanism in terms of the type and nature of the polymer membranes and solvent molecules. None of the polymer membranes studied have shown any degradative reactions and significant swelling in the presence of the chosen solvents. The present results would have applications in areas such as those including the studies on barrier properties, separation science, and chemical pond lining, etc.     

Molecular transport of n‐alkanes through diol chain‐extended polyurethane membranes

Molecular transport of n‐alkanes was investigated by calculating sorption, diffusion, and permeation of liquids through the diol chain‐extended polyurethane (PU) membranes in the temperature interval 25–60°C. Sorption experiments were performed gravimetrically. Diffusion coefficients were calculated from Fick's equation. These results showed a dependency on the nature and size of interacting n‐alkane molecules as well as morphology of the chain‐extended PUs. Transport kinetics followed an anomalous trend. Using the temperature‐dependent transport parameters, activation energies were calculated for diffusion and permeation processes using an Arrhenius equation. The van't Hoff relationship was used to obtain enthalpy and entropy of sorption. Concentration profiles of liquids through PU membranes were computed using Fick's equation, solved under appropriate initial and boundary conditions. A correlation was attempted between transport properties of liquids and physicomechanical properties of PU membranes. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 874–882, 2005     

Sorption,diffusion, and permeation of esters,aldehydes, ketones,and aromatic liquids into tetrafluoroethylene/propylene at 30, 40, and 50°c

The coefficients of sorption, diffusion, and permeation for five organic esters, three aldehydes, one cyclic ketone, and three substituted aromatic liquids have been calculated for tetrafluoroethylene/propylene copolymer membranes at 30, 40, and 50°C with the sorption–gravimetric technique. With the sorption data, the concentration‐independent diffusion coefficients have been calculated from Fick's diffusion equation. Analytical solutions of Fick's equation under suitable boundary conditions have been obtained so that the liquid concentration profiles in the polymeric membranes at different times and different depths of liquid penetration could be computed. Because of the linearly increasing trend of the diffusion coefficients with temperature, efforts have been made to estimate Arrhenius parameters. Experimental values and the computed quantities have been used to determine the membrane–solvent interactions and to propose suitable applications for the membranes under investigation in various situations. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3201–3209, 2003     

Sorption and migration of aliphatic organic esters into VITON® fluoroelastomer membranes

Sorption and migration of six aliphatic esters into four VITON^® fluoroelastomers were studied by a gravimetric sorption method in the temperature interval of 30–60°C. Fick's equation was used to obtain diffusion coefficients. The dependence of fluorine contents and the polymer morphology on the sorption and diffusion characteristics of esters was investigated. The permeability coefficients were obtained from the sorption and diffusion data. Fick's equation was solved to compute the concentration profiles of liquids at various locations within the membrane materials using initial and boundary conditions. These profiles were compared with those obtained from the numerical method based on finite difference technique. Activation parameters for diffusion and sorption were calculated using the Arrhenius relationship. These results were discussed in terms of molecular size and shapes of the esters. For higher esters, namely, n- and iso-amyl acetates, a concentration dependency of the diffusion coefficient was investigated. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1223–1235, 1997     

A study on molecular transport of organic esters and aromatics into viton fluoropolymers

Molecular transport of organic liquids into Viton fluoropolymers has been investigated by a sorption—desorption gravimetric method. Diffusion coefficients have been calculated from Fick's equation. The sorption—desorption results have been used to calculate the concentration profiles by solving Fick's diffusion equation under suitable boundary conditions. A numerical method based on the finite difference technique was also used to calculate the concentration profiles of liquids as a function of sorption time and thickness of the Viton fluoropolymers. The dependence of sorption, desorption, diffusion, and permeation properties of the liquids on temperature showed a significant effect. The Arrhenius activation parameters have been estimated for diffusion, permeation, and sorption processes. The experimental and calculated results are discussed to study the type and nature of interactions between Viton fluoropolymers and the solvent molecules. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 717–723, 1997     

Sorption and Diffusion of Organic Liquids into Fluoroelastomer Membranes

Abstract

Sorption and diffusion of organic liquids into fluoropolymer (FC-2179) membranes have been investigated from 30 to 60°C using a gravimetric method. Diffusion coefficients, percent mass uptake, and apparent activation energies for the transport processes have been estimated. Diffusion coefficients of the liquids into the membrane have been computed from Fick's relation. A Flory–Huggins-type interaction parameter was obtained from the solubility parameter concept. Furthermore, the activation parameter values and heat of sorption data have been studied in terms of heat of mixing. The values of diffusion coefficients did not show any considerable dependence on solvent concentration. However, solvent transport as analyzed from an empirical equation was found to be of the anomalous type. Molecular transport also showed a dependence on the chemical nature of the liquids. The concentration profiles of liquids have been calculated at different penetration depths of the membrane at different time intervals by solving Fick's differential equation under suitable initial and boundary conditions. A numerical method based on the finite difference technique was also used to predict the concentration profiles of liquids, and these are compared with the profiles computed from an analytical solution of Fick's equation.     

Solvent Migration and Drying Phbnoubnon of Polymeric Blends of Ethylene-Propylbnb Random Copolymbr and Isotactic Polypropylbnb in the Prbsbncb of Monocyclic Aromatic Liquids at Tbwbraturbs Bbtukbn 25-70°C.

Solvent sorption and drying performance of engineering polymeric blends of ethylene-propylene random copolymer and isotactic polypropylene in the presence of aromatic liquid: has been studied in the temperature interval 25-70°C. The drying of the polymer is studied from the desorption and redesorption experiments. The present results indicate that the rate of solvent migration and the drying phenomenon is controlled by internal mass transfer of solvent molecules within the polymer matrix. A technique is developed to study the sorption (S) -desorption (D) - resorption (RS)-redesorption (RD) i.e., S-D-RS-RD of the polymer sheets. The S-D-RS-RD experiments are a convenient measure of knowing the continuous weight loss of the polymer during long-term solvent exposure.