Solubility Parameter Of Solvent Research Articles

Chemical compatibility of PU/PAN interpenetrating polymer network membrane with substituted aromatic solvents

Polyethylene glycol (PEG)-based polyurethane/polyacrylonitrile (PU/PAN, 50/50) semi-interpenetrating polymer network (SIPN) membrane has been studied from sorption/desorption cycles and diffusion behaviour with substituted aromatic probe molecules at 20, 40 and 60 °C. Sorption/desorption cycles have been repeated to evaluate polymer–solvent interaction. Organic solvents taken up or given out by IPN are measured periodically till equilibrium. Using these data, sorption ( S), diffusion ( D) and permeation ( P) coefficients have been calculated from Fick's equation. Sorption data is correlated with solubility parameter of solvents and polymer. It was found that solvents of comparable solubility parameter with IPN interact more and thus there is an increase in sorption. Molecular mass between cross-link has been calculated using Flory Rehner equation. The cross-link density and degree of cross-linking of the membrane is calculated. From the temperature dependence of sorption and diffusion coefficients, the Arrhenius activation parameters like activation energy for diffusion ( E D ) and permeation ( E P ) processes have been calculated. Furthermore, the sorption results have been interpreted in terms of thermodynamic parameters such as change in enthalpy (Δ H) and entropy (Δ S). Concentration profiles of penetrants at different penetration depths in the polymer sample at different time intervals have also been calculated theoretically from a solution of Fick's equation under appropriate initial boundary conditions.

Sladky KK, Krugner-Higby L, Meek-Walker E, et al. Serum concentrations and analgesic effects of liposome-encapsulated and standard butorphanol tartrate in parrots. Am J Vet Res 67:775-781, 2006

This study describes how protein release from polymer matrices correlate with simple measurements on the intrinsic viscosity of the polymer solutions used for casting the matrices and calculations of the solubility parameters of polymers and solvents used.Matrices of poly(dl-lactide-co-glycolide) (PLGA) were cast with bovine serum albumin (BSA) as a model drug using different solvents (acetone, dichloromethane, ethanol and water). The amount of released protein from the different matrices was correlated with the Hildebrand and Hansen solubility parameters of the solvents, and the intrinsic viscosity of the polymer solutions. Matrix microstructure was investigated by transmission and scanning electron microscopy (TEM and SEM). Polycaprolactone (PCL) matrices were used in a similar way to support the results for PLGA matrices.The maximum amount of BSA released and the release profile from PLGA matrices varied depending on the solvent used for casting. The maximum amount of released BSA decreased with higher intrinsic viscosity, and increased with solubility parameter difference between the solvent and polymer used. The solvent used also had an effect on the matrix microstructure as determined by TEM and SEM. Similar results were obtained for the PCL polymer systems.The smaller the difference in the solubility parameter between the polymer and the solvent used for casting a polymer matrix, the lower will be the maximum protein release. This is because of the presence of smaller pore sizes in the cast matrix if a solvent with a solubility parameter close to the one of the polymer is used. Likewise, the intrinsic viscosity of the polymer solution increases as solubility parameter differences decrease, thus, simple measurements of intrinsic viscosity and solubility parameter difference, allow the prediction of protein release profiles.

Determination of solubility profiles of eflucimibe polymorphs: Experimental and modeling

This work presents the determination of the phase diagram of two polymorphs of Eflucimibe in pure solvents and solvent mixtures at different temperatures. Solid phase changes were analysed by Differential Scanning Calorimetry. Solubility measurements show that the solubility of the two forms are very similar. Experimental data obtained in ethanol, reported in a Van t'Hoff plot, exhibit a transition temperature around 265K. A single maximum is observed when solubility is plotted against the solubility parameters of solvents or solvent mixture and it is not related to a solid phase change. This phenomenon, known as a positive synergetic effect, has been explained in term of evolution of solute-solvents polar interactions. Several thermodynamics models (UNIFAC, UNIQUAC, Wilson, Scatchard Hildebrand…) were tested in order to predict the Liquid–Solid Equilibrium for this system. The semi empirical model UNIQUAC gives the best fit. The results obtained are in good agreement with the experimental data (mean deviation lower than 5%) and the solubility maximum found experimentally for each polymorph is also well described.

Recrystallization of a Pharmaceutical Compound Using Liquid and Supercritical Antisolvents

Sulfabenzamide was recrystallized from its solutions by using liquid and supercritical fluid as antisolvents. The drug compound was dissolved in various organic solvents, such as acetone, methanol, ethanol, and ethyl acetate, and the solutions came into contact with two antisolvents, water (liquid) and carbon dioxide (supercritical fluid). Variations of the habit, particle size, and the thermal behavior of the crystals were examined to investigate the effect of the operating temperature, type of solvent and antisolvent, mixing method, and the presence of ultrasound. Crystal habits such as acicular, columnar, prismatic, equant, and tabular were obtained depending on the solvents and antisolvents used. Larger crystals with a broader distribution were produced at higher temperatures, and crystal size was reduced when the solution was sonicated while precipitation occurred. The variations of crystal size were correlated with the use of solubility parameters of solvents and antisolvents. The thermal analysis o...

Are solubility parameters relevant to supercritical fluids?

Expressions are presented, based on equations of state, for the estimation of the solubility parameters of supercritical fluids. These expressions depend on the critical constants and the density of the fluids as well as their acentric factors if not conformal with Lennard–Jones fluids. For those that are conformal an alternative expression depending on the Lennard–Jones parameters is presented. A correlation of solubility parameters of room temperature solvents with the Kamlet–Abboud–Taft solvatochromic dipolarity/polarizability parameters is extended to cover also supercritical fluids.

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 (Δ S) and enthalpy (Δ H) 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.

Solvatochromic Linear Solvation Energy Relationships (LSER) for Solubility of Gases in Various Solvents by Target Factor Analysis

A linear solvation free energy relationship has been conducted to study the effects of solvent and solute properties on the free energy of solvation of inert gases and normal alkanes in different solvents. Factor analysis combined with target factor analysis was used to identify and quantify the factors controlling the variation of free energies of solvation, without the need to postulate any priori hypothetical method. Factor analysis of the solvation data revealed that there are two factors affecting the solubility of both types of gases in non-polar as well as polar solvents. Target testing of the solvent parameters indicated that the Hildebrand solubility parameter of solvents is the major factor controlling the solubility of gases. Moreover, it was found that the coefficient of the Hildebrand solubility parameter in the linear solvation free energy equations has linear correlation with energy of vaporization and Lennard-Jones force parameter of inert gases and number of carbon atoms and energy of vaporization of normal alkanes.

The Effect of Adding Organic Solvents on the Phase Behavior in Water/Surfactant/scCO<sub>2</sub> Microemulsion in Supercritical State

Water/CO2 (W/C) microemulsion was formed by sodium salt of bis(2,2,3,3,4,4,5,5-octa fluoro-1-pentyl)-2-sulfosuccinate and the phase behavior of this emulsion was investigated in supercritical state. In addition, the change of the phase behavior of W/C microemulsion was observed when various organic solvents were added into this microemulsion. The added organic solvents are isopropanol, n-propanol, ethanol, methanol, pyridine, 2-methoxyethanol, tetrahydrofuran, acetonitrile, acetone, and 1,4-dioxane. According to the results, the phase behavior of W/C microemulsion depended on the temperature and pressure and the microemulsion was thermodynamically stable in the special range of pressure. In case of W/C microemulsion with organic solvents, the phase behavior of this system was affected by the solubility parameter of organic solvents.

Solubility prediction of anthracene in binary and ternary solvents by artificial neural networks (ANNs)

Solubility of anthracene in binary and ternary solvent systems was modeled by artificial neural networks (ANNs) technique. The results obtained using the ANN method indicated that the solubility of anthracene in mixed solvents could be calculated using the mole fraction solubilities in pure solvents, mole/volume fraction of solvents and solvent's solubility parameters. The topology of neural network was optimized empirically and optimum topology was a 6-6-1 architecture for binary and 9-6-1 for ternary mixtures. The solubility of anthracene in mixed solvents was estimated by means of ANN and the predicted solubility was compared with experimental solubility data. The overall absolute percentage mean deviation (OPMD) for trained ANNs using all data points in 25 binary and 30 ternary solvent systems were 0.16 and 0.20%, respectively. A minimum number of data points from binary and ternary solvents have been employed to train the ANN and solubility at other solvent compositions has been predicted. The OPMD obtained for solubility in binary and ternary solvents were 0.67 and 0.27%, respectively. The trained network with 25 binary data sets was applied to predict the solubility in 16 other binary solvent systems and the OPMD obtained is 15.32%. The results of ANNs were also compared with similar numerical analyses carried out using multiple linear regression models and found that the ANN method is generally promising more accurate calculations.

Synthetic hydrogels 3. Solvent effects on poly(2-hydroxyethyl methacrylate) networks

Poly(2-hydroxyethyl methacrylate) networks were synthesized in aqueous solutions of propylene glycol, ethylene glycol, ethylene glycol monomethyl ether, or ethylene glycol dimethyl ether and the influences of solvent on phase separation during the polymerization process studied. Results from conversion-phase diagrams, turbidity measurements, swelling studies, and viscosity measurements show that the phase separation process is dependent upon the solubility parameter of the organic solvent, the instantaneous monomer concentration at each stage of the gel formation process, and the crosslinker content of the reaction mixture.

Solution rheology of hydrophobically modified associative polymers: Solvent quality and hydrophobic interactions

The rheological behavior of a model hydrophobically modified alkali soluble emulsion (HASE) polymer, comprised of a random copolymer backbone of methacrylic acid and ethylacrylate and pendant hydrophobic macromonomers, is examined in cosolvents of water and propylene glycol (PG) of different proportions. We find the solvent solubility parameter to have a direct impact on both the steady and dynamic behavior of the polymer solutions. In particular, scaling of the relative viscosity (ηrel) and the elastic modulus (G′) at a fixed frequency with the solvent solubility parameter (δs) reveals the presence of two distinct regimes with different dependences on δs. In “water-rich” solvents, both ηrel and G′ show a strong dependence on δs in contrast to “PG-rich” solvents, in which there is slight or no dependence on δs. The concentration dependences of both ηrel and G′ are also found to be different in water-rich solvents from that in PG-rich solvents. In water-rich solvents, ηrel and G′ reveal power-law dependences with exponents of 2.5 and 3.2, respectively, compared to exponents of 1.4 and 2.3 in PG-rich solvents. The different behavior in PG-rich solvents is ascribed to the presence of minimal hydrophobic associations, with the polymer behavior analogous to that of unmodified polymers without hydrophobes. This hypothesis is supported by the similarity in ηrel scaling with concentration observed for both the HASE polymer in PG-rich solvents and a similar polymer without the hydrophobes in both solvents. The lack of hydrophobic interactions in the PG-rich solvents may be attributed to the observed decrease in polymer coil dimension together with a lower tendency of the hydrophobes to form micelles in less polar media.

Methods of Calculation of Solubility Parameters of Solvents and Polymers

AbstractFor Abstract see ChemInform Abstract in Full Text.

Prediction of Polymer Thermal Diffusion Coefficients from Polymer-Solvent Interaction Parameters: Comparison with Thermal Field Flow Fractionation and Thermal Diffusion Forced Rayleigh Scattering Experiments

In this study a model that allows the qualitative prediction of polymer thermal diffusion coefficients from polymer-solvent interaction parameters is presented. The Flory-Huggins lattice theory served as a starting point for the thermal diffusion model. From this model it follows that D T is determined by the temperature dependence of the polymer-solvent interaction parameter ( h ), the segmental mobility of the polymer chain, and the polymer concentration. In agreement with literature data, the model predicts that D T is independent of the molecular mass of the polymer, D T increases with temperature, and D T is strongly dependent on the interaction between the polymer and the solvent. Furthermore, it follows from the model that D T should decrease with concentration. A good qualitative agreement with experimental data has been found. In order to study the potentials of the model, the D T values of polystyrene (PS) in several solvents were predicted. The required temperature-dependent polymer-solvent interaction parameters were calculated from Hildebrand's solubility parameters of the polymer and of the solvent. The solvent's solubility parameters were estimated using Lee and Kesler's generalized thermodynamic equations of state. The polymer solubility parameters were taken from the literature. Lack of data complicated the comparison. However, a good agreement for PS in THF, MEK, dioxane, and cyclohexane was found. Thermal diffusion values predicted for PS in several aromatic solvents were, however, significantly low. Still, the overall result is satisfactory considering the fact that the Flory-Huggins theory is a highly simplified polymer-solvent theory that was never intended to be used for quantitative purposes. Polymer thermal diffusion model Thermal field-flow fractionation Polymer-solvent interaction parameter Thermal diffusion forced Rayleigh scattering

Solvent Selection for Gas Antisolvent Precipitation Process

The precipitation of biphenyl from twenty organic solvents using carbon dioxide as anti solvent was examined in this study. The experimental results showed that even though a large volume expansion of some solvents after the addition of the compressed CO2, biphenyl could not be precipitated due to that CO2 acted as a cosolvent rather than an antisolvent in these operations. The criterion for the precipitation of biphenyl from a solvent was proposed as that the solubility parameter of the solvent should be larger than 17.4 MPa1/2 but smaller than that of biphenyl (21.6 MPa1/2). When the solubility parameter of a solvent was closer to that of biphenyl, more biphenyl was precipitated. For a solvent not causing the precipitation of biphenyl, the proposed criteria can be applied to determine what the other solvent and the minimum amount should be added into the solvent to result in a precipitation.

Dispersion and Flocculation Behavior of Fine Metal Oxide Particles in Various Solvents [Translated]<sup>†</sup>

The objective of this study is to investigate the relation between the f locculation and dispersion of Al2O3, TiO2 and Fe2O3 particles and the properties of solvents such as dielectric constant and solubility parameters. The median diameter of these metal oxide perticles was measured in many organic solvents. The effect of the kind of solvent on the f locculation/dispersion behavior of metal oxide particles was evaluated from these results. Hansen’s solubility parameters with three dimensions were applied to the evaluation of the f locculation/dispersion behavior for fine metal oxide particles in organic solvents. The numeral balance among the Hansen’s solubility parameters of various solvents was plotted in a triangular chart, and then the points of solvents with similar median diameter of the particle were linked. In the triangular chart, these linked lines were not intersected each other and there was the specific point at which the best dispersibility of the particles was obtained.

Volumetric properties, viscosities and refractive indices of binary mixed solvents containing methyl benzoate

Densities, dynamic viscosities, and refractive indices of the binary mixed solvents of methylbenzoate with a set of eleven organic solvents provided with six carbon atoms but different structure and functional groups were measured over the whole composition range. Thermodynamic, transport, solubility, and electrical properties were analyzed for all systems; from the experimental quantities, excess and mixing properties were deduced and interpreted in terms of intermolecular interactions and structural changes upon mixing. Mixing viscosities and excess Gibbs energies of activation for viscous flow support the role played by the size of the cosolvent on the mixture behaviour. Analysis in terms of solvent solubility parameters was in convincing good agreement with experimental results. The Soave and Peng–Robinson equations of state and the Wong–Sandler mixing rule are used to correlate volumetric properties. The predictive ability of several one-parameter and two-parameter viscosity models was also tested.

The effect of branching of alkanes on the liquid–liquid equilibrium of oligostyrene/alkane systems

Liquid–liquid equilibria were measured in a series of solutions of an oligostyrene (1241 amu) in selected linear, branched and cyclic lower alkanes. Correlations between the solubility parameters of the alkane solvents and the experimental upper critical solution temperatures (UCSTs) are reported.

Intrinsic Viscosity Variation in Different Solvents for Dendrimers and Their Hybrid Copolymers with Linear Polymers

The intrinsic viscosity of narrow molecular mass distribution polystyrene standards, poly(benzyl) ether dendrimers, and their hybrid block copolymers was measured in a variety of solvents. The relative change in the intrinsic viscosity for all these polymers was almost equivalent, indicating that poly(benzyl ether) dendrimers expand and contract quite readily with a change in solvent. The intrinsic viscosity maximum for all polymers was found to occur at essentially the same solvent solubility parameter demonstrating that the thermodynamic interaction with the selected range of solvents was also equivalent. The intrinsic viscosity for hybrid copolymers in a good solvent for both components was found to fall well below the intrinsic viscosity for neat polystyrene at intermediate molecular masses. Below and above this mass range the intrinsic viscosity was quite similar to polystyrene. Yet, the transition for intermediate to high molecular mass behavior was quite sharp as seen through a rapid intrinsic visc...

Gas–liquid chromatographic study of polystyrene–n‐alkane interactions

AbstractGas–liquid chromatography is used to study the thermodynamic interactions between polystyrene and n‐alkanes (C6–C10). Polystyrene is used as a stationary phase with n‐alkanes as the probe molecules. Retention times and specific retention volumes are measured over the temperature interval of 60 to 170°C. Partial molar free energy of mixing, polymer–solvent interaction parameter, glass‐transition temperature, and solubility parameter of polystyrene at infinite dilution are calculated. Experimental results are discussed in terms of the theoretical calculations and size of the probe molecules. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1291–1298, 2001

Prediction of solubility parameters using the group-contribution lattice-fluid theory

A formulation for the solubility parameter based on the group-contribution, lattice fluid equation of state was derived. The solubility parameters of pure liquid solvents, polymers, copolymers, and liquid mixtures were calculated and compared against the best available data. This investigation was conducted on pure components and mixtures of alkanes, alkenes, ketones, ethers, acetates, alcohols, chlorinated molecules, and cyclic and aromatic solvents. The capabilities of the model to distinguish between two isomers and to predict the solubility parameter of supercritical fluids and their mixtures were also studied. The predicted values are generally good, although the error increases when hydrogen bonding is present. A primary application of the procedure is for the prediction of the solubility parameters of polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 197–206, 2001