Miscibility Research Papers - Academia.edu (original) (raw)

Gas injection is the second largest enhanced oil recovery process, next only to thermal processes used in heavy oil fields. To increase the extent of the reservoir contacted by the injected gas, the gas is generally injected... more

Gas injection is the second largest enhanced oil recovery process, next only to thermal processes used in heavy oil fields. To increase the extent of the reservoir contacted by the injected gas, the gas is generally injected intermittently with water. This mode of injection, called water-alternating-gas (WAG), is being widely practiced in the oil fields.This experimental study is aimed at

Glass transition temperature Tg values characterize pure polymers, polymer blends, copolymers, as well as matrices in polymer-based composites. Tgs as function of composition reflect miscibility (or lack of it) and determine all... more

Glass transition temperature Tg values characterize pure polymers, polymer blends, copolymers, as well as matrices in polymer-based composites. Tgs as function of composition reflect miscibility (or lack of it) and determine all properties. We present a new equation for the dependence of Tg on composition in blends as well as in copolymers. We compare results obtained from earlier equations (Fox,

The first public version of TernAPI (ternary diagrams assessment programming interface) software package for ternary phase diagrams calculation by the convex hull method has been developed. Its reliability and efficiency have been proved... more

The first public version of TernAPI (ternary diagrams assessment programming interface) software package for ternary phase diagrams calculation by the convex hull method has been developed. Its reliability and efficiency have been proved on a large set of systems of different kind: organic liquids and fluids mixtures, water solutions, salts, oxides, metallic alloys. A remarkable advantage of TernAPI is a stable work in the case of isolated miscibility gaps (" islands ") described by a uniform Gibbs energy surface equation. It also contains several improvements of phase diagram calculation algorithm, a new module for x–T diagrams polythermal sections calculation and possibility of optimization of thermodynamic models parameters. NRTL model parameters for the acetic acid–N,N-dimethylformamide–cyclohexene ternary system have been optimized in this work. The specialized language based on Ruby and YAML is used for the description of thermodynamic models of phases.

In the present study, the results from viscometric measurements, tensile tests and Fourier transform infrared spectroscopy (FTIR) of polymer blends containing collagen (Coll) and hyaluronic acid (HA) with and without chitosan (Ch) are... more

In the present study, the results from viscometric measurements, tensile tests and Fourier transform infrared spectroscopy (FTIR) of polymer blends containing collagen (Coll) and hyaluronic acid (HA) with and without chitosan (Ch) are presented. The viscosity interaction parameter of each polymer in 0.1 mol·dm −3 CH 3 COOH/0.3 mol·dm −3 NaCl solution for the collagen and 0.3 mol·dm −3 NaCl or 0.1 mol·dm −3 HCl solution for the hyaluronic acid and 0.1 mol·dm −3 CH 3 COOH/0.3 mol·dm −3 NaCl solution for the chitosan as well as the two-component blend systems and the ternary blend systems have been determined. These studies indicated that collagen/hyaluronic acid blends were miscible at any composition (Coll/HA: 80/20, 50/50, 20/80) in 0.1 mol·dm −3 CH 3 COOH/0.3 mol·dm −3 NaCl and 0.1 mol·dm −3 HCl at 25 °C. In the case of Coll/HA/Ch ternary blends, the polymeric components were partially miscible. The mechanical properties of films such as tensile strength and Young's modulus depend on the blend composition. Coll/HA blends possessed a tensile strength and Young's modulus of 16.3–57.6 MPa and 1.0–1.9 GPa, respectively. The addition of chitosan to the blend led to an increase in tensile strength by approximately 50%. The results of FTIR analysis suggested that there was the existence of intermolecular interactions between functional groups of polymers.

The cocrystallization landscape of benzamide and urea interacting with aliphatic and aromatic carboxylic acids was studied both experimentally and theoretically. Ten new cocrystals of benzamide were synthesized using an oriented samples... more

The cocrystallization landscape of benzamide and urea interacting with aliphatic and aromatic carboxylic acids was studied both experimentally and theoretically. Ten new cocrystals of benzamide were synthesized using an oriented samples approach via a fast dropped evaporation technique. Information about types of known bi-component cocrystals augmented with knowledge of simple binary eutectic mixtures was used for the analysis of virtual screening efficiency among 514 potential pairs involving aromatic carboxylic acids interacting with urea or benzamide. Quantification of intermo-lecular interaction was achieved by estimating the excess ther-modynamic functions of binary liquid mixtures under supercooled conditions within a COSMO-RS framework. The smoothed histograms suggest that slightly more potential pairs of benzamide are characterized in the attractive region compared to urea. Finally, it is emphasized that prediction of cocrystals of urea is fairly direct, while it remains ambiguous for benzamide paired with carboxylic acids. The two known simple eutectics of urea are found within the first two quartiles defined by excess thermodynamic functions, and all known cocrystals are outside of this range belonging to the third or fourth quartile. On the contrary, such a simple separation of positive and negative cases of benzamide miscibility in the solid state is not observed. The difference in properties between urea and benzamide R2,2(8) heterosynthons is also documented by alterations of substituent effects. Intermolecular interactions of urea with para substituted benzoic acid analogues are stronger compared to those of benzamide. Also, the amount of charge transfer from amide to aromatic carboxylic acid and vice versa is more pronounced for urea. However, in both cases, the greater the electron withdrawing character of the substituent, the higher the binding energy, and the stronger the supermolecule polarization via the charge transfer mechanism.

While the knowledge about the retrograde condensation and condensing-gas drive phenomena Is not new their utilization in production-stimulation and simulation of the natural gas and NGL reservoirs has been delayed due to the lack of... more

While the knowledge about the retrograde condensation and condensing-gas drive phenomena Is not new their utilization in production-stimulation and simulation of the natural gas and NGL reservoirs has been delayed due to the lack of accurate predictive computer algorithms. In this report the groundwork for accurate computation and prediction of the behavior of reservoir fluids under retrograde condensation and in condensing-gas-drive conditions are presented. It is shown that by using equations of state It Is possible to calculate accurately the minimum miscibility conditions and solubility of heavy and Intermediate hydrocarbons in miscible solvents (gases and gaseous mixtures) and phase behavior (dew point and bubble point in VLE and VLLE cases) of complex reservoir fluids. The bases of this research · lie in statistical mechanical mixing rules and the conformal solution theory of polar fluid mixtures. It Is shown that through equations of state one can predict the following properties of the reservoir fluid systems: (I) The minimum miscibility conditions and solubilities of intermediate and heavy hydrocarbons in miscible solvents. [ii) The effect of mixed miscible solvents and entrainers on lowering the minimum References and figures at end of paper. miscibility pressure of heavy components of reservoir fluids. [iii] The role of variations In temperature, pressure, and solvent composition on the miscibility and solubilitiies. [iv] Flash (dew point and bubble point) calculation for complex reservoir fluids in VLE and VLLE cases.

The properties of diglycidyl ether of bisphenol-A epoxy resin toughened with poly(ether sulfone ether ketone) (PESEK) and poly(ether sulfone) (PES) polymers were investigated. PESEK was synthesised by the nucleophilic substitution... more

The properties of diglycidyl ether of bisphenol-A epoxy resin toughened with poly(ether sulfone ether ketone) (PESEK) and poly(ether sulfone) (PES) polymers were investigated. PESEK was synthesised by the nucleophilic substitution reaction of 4,4’-difluorobenzophenone with dihydroxydiphenylsulfone using sulfolane as solvent and potassium carbonate as catalyst at 230 °C. The T g–composition behaviour of the homogeneous epoxy resin/PESEK blend was modelled using Fox, Gordon–Taylor and Kelley–Bueche equations. A single relaxation near the glass transition of epoxy resin was observed in all the blend systems. From dynamic mechanical analysis, the crosslink density of the blends was found to decrease with increase in the thermoplastic concentration. The storage modulus of the epoxy/PESEK blends was lower than that of neat resin, whilst it is higher for epoxy/PES blends up to glass transition temperature, thereafter it decreases. Scanning electron microscopic studies of the blends revealed a homogeneous morphology. The homogeneity of the blends was attributed to the similarity in chemical structure of the modifier and the cured epoxy network and due to the H-bonding interactions between the blend components. The fracture toughness of epoxy resin increased on blending with PESEK and PES. The increase in fracture toughness was due to the increase in ductility of the matrix. The thermal stability of the blends was comparable to that of neat epoxy resin.

Poly lactic acid (PLLA) is a promising biopolymer, obtained from polymerization of lactic acid that is derived from renewable resources through fermentation. The characteristic brittleness of PLLA is attributed to slow crystallization... more

Poly lactic acid (PLLA) is a promising biopolymer, obtained from polymerization of lactic acid that is derived from renewable resources through fermentation. The characteristic brittleness of PLLA is attributed to slow crystallization rates, which results in the formation of the large spherulites. Its glass temperature is relative high, above room temperature and close to 60 °C, and therefore its applications are limited. The additives poly((R)-3-hydroxybutyrate) (PHB), poly(vinyl acetate) (PVAc) and tributyl citrate (TBC) were used as compatibilizers in the
biodegradable polymer blend of (PLLA/PPC). Results from DSC and POM analysis indicated that the blends of PLLA
and PPC are immiscible. However, the blends with additives are miscible. TBC as plasticizer was added to PLLA to
reduce its Tg. PVAc was used as compatibilizer to improve the miscibility between PLLA and PPC. FT-IR showed
about 7 cm–1 shift in the C=O peak in miscible blends due to physical interactions. POM experiments together with the
results of DSC and WAXD showed that PHB enhances the crystallization behavior of PLLA by acting as bio nuclei
and the crystallization process can occur more quickly. Consequently an increase was observed in the peak intensity
in WAXD.

The compatibilizing effect of functionalized low density polyethylene (PE-LD) on PE-LD/polyamide 6 (PA6)/ethylene-propylene-diene terpolimer (EPDM) ternary blends has been studied. Compatibility was evaluated by means of differential... more

The compatibilizing effect of functionalized low density polyethylene (PE-LD) on PE-LD/polyamide 6 (PA6)/ethylene-propylene-diene terpolimer (EPDM) ternary blends has been studied. Compatibility was evaluated by means of differential scanning calorimetry, which was used also for studying the melting and crystallization phenomena. Torque-time measurements were performed in order to determine the processing behavior. The functionalized PE-LD modify the processing behavior, the crystallinity degree of PE-LD and PA6 and impact properties of the studied blends. These effects result from chemical reactions between functional groups of compatibilizing agents and the end groups of polyamide.

The miscibility of the poly(vinyl chloride)/poly(methylmethacrylate) system were improved by introducing pyridine units into poly(methylmethacrylate) main. For this purpose, we have synthesized through a radical polymerization a series of... more

The miscibility of the poly(vinyl chloride)/poly(methylmethacrylate) system were improved by introducing pyridine units into poly(methylmethacrylate) main. For this purpose, we have synthesized through a radical polymerization a series of methylmethacrylate-co-vinyl-4-pyridine copolymers of different compositions and carried out a comparative study by viscosimetry, differential scanning calorimetry, and Fourier transform infrared spectroscopic (FTIR) methods. The viscosimetric analysis using the Krigbaum-Wall, K. K. Chee, and Compos approaches revealed that, the Poly(vinyl chloride)/poly(methylmethactylate-co-4-vinylpyridine)(PVC/MMA4VP-15) at 15 wt % of 4-vinylpyridine systems in tetrahydrofuran are completely miscible in all proportions. The differential scanning calorimetry analysis confirmed the miscibility of these systems in all proportions by the appearance of only one glass transition temperature between those of the two pure constituents. The Kwei and Schneider approaches showed also the miscibility of this system, which is due to the specific interactions between the acidic hydrogen atom of PVC and the nitrogen of MMA4VP-15. The use of FTIR method has confirmed the occurrence of this kind of interactions by broadening and shifting of the involved functional groups vibration bands. In this work, we have also carried out a preliminary test of sorption of THF aqueous solution by PVC and PVC/MMA4VP-15 blend membranes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Lattice fluid theory for hydrogen bonded fluid mixtures h_ as been extended to predict phase stability and miscibility of hydrogen bonded polymer mixtures. Miscibility regions and spinodal curves f o r mixtures of ethylene vinyl phenol... more

Lattice fluid theory for hydrogen bonded fluid mixtures h_ as been extended to predict phase stability and miscibility of hydrogen bonded polymer mixtures. Miscibility regions and spinodal curves f o r mixtures of ethylene vinyl phenol copolymer (PE-co-PVPh) with Poly Ethylene Oxide (PEO), Poly Vinyl Acetate (PVAc) and Poly Caprolactone (PCL) have been presented. The effect of change in the number of proton donor and proton acceptor functional groups on compatibilizing polymer mixtures and polymer miscibility has been considered.

Molecular simulations are the most important tools to predict the properties of polymers and their blends. In this work, we have predicted the blend incompatibility of poly(n-vinyl pyrrolidone) (PVP) and poly(bisphenol-A-ether sulfone)... more

Molecular simulations are the most important tools to predict the properties of polymers and their blends. In this work, we have predicted the blend incompatibility of poly(n-vinyl pyrrolidone) (PVP) and poly(bisphenol-A-ether sulfone) (PES). Atomistic simulations were performed to compute the Flory-Higgins interaction parameter over all the compositions ranging from 90 to 10% of the individual polymers, which confirmed that the blends are incompatible (Bhattacharya et al., J Membr Sci 2003, 227, 23). Kinetics of phase separation was examined via density profiles calculated using MesoDyn approach. For incompatible blends, the critical value of 0.32 computed from the Flory-Huggins theory agreed with the value of 0.29, suggesting the validity of our approach. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The influences of molecular weight and m-LLDPE comonomer type on the miscibility of m-LLDPE with LDPE in the melt state were investigated with rheological methods. Dynamic, steady shear and transient measurements were carried out in an... more

The influences of molecular weight and m-LLDPE comonomer type on the miscibility of m-LLDPE with LDPE in the melt state were investigated with rheological methods. Dynamic, steady shear and transient measurements were carried out in an ARES rheometer at 190° ...

Miscibility studies of chitosan/polyacrylamide (Ch/PAM) and chitosan/partially hydrolyzed polyacrylamide (Ch/HPAM) blends of different compositions were investigated using viscometric method. The intrinsic viscosity, ([η]), and the... more

Miscibility studies of chitosan/polyacrylamide (Ch/PAM) and chitosan/partially hydrolyzed polyacrylamide (Ch/HPAM) blends of different compositions were investigated using viscometric method. The intrinsic viscosity, ([η]), and the viscosity interaction parameters, (b m), have been determined for the binary (solvent/polymer) and ternary (solvent/polymer A/polymer B) systems. Degree of miscibility of these polymer blends was estimated on the basis of two criteria. These studies indicate that chitosan/polyacrylamide and chitosan/partially hydrolyzed polyacrylamide are miscible at any composition in 0.1 mol·dm −3 CH 3 COOH + 0.2 mol·dm −3 NaCl at 25 °C. The influence of blend composition on mechanical properties was also investigated in this study. Ch, PAM, HPAM and their blend films were prepared by casting technique. The mechanical properties such as ultimate tensile strength and Young modulus depend on the weight fraction of chitosan and were changed irregularly. The FTIR spectroscopy also supports the obtained results. The miscibility of polymer mixtures is related to the interactions between the functional groups of the polymeric components.

Hydroxylated neem seed oil (HNSO) was synthesized and blended with polyvinyl acetate (PVA) to develop HNSO/PVA copolymer binder for emulsion paint formulation. Some physical properties of the copolymer resin such as viscosity, gel time,... more

Hydroxylated neem seed oil (HNSO) was synthesized and blended with polyvinyl acetate (PVA) to develop HNSO/PVA copolymer binder for emulsion paint formulation. Some physical properties of the copolymer resin such as viscosity, gel time, density, melting point, refractive index, moisture uptake, elongation at break and water solubility were determined. The results from studies indicated that viscosity, refractive index, gel time and elongation at break increases with increase in HNSO concentration in PVA/HNSO copolymer composite. However, density, melting point, water solubility and moisture uptake decreases with HNSO concentration in the composite. This result is a pointer to the fact that the traditional problems associated with PVA can be address or reduce by HNSO/PVA blend. The results of the physico-chemical properties of HNSO/PVA copolymer binder were in conformity with the results in the literature values.