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

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.

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

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.

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.

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

A novel four-arm radial block co-polymer (A-B)4 obtained by atom transfer radical polymerization (ATRP) and a random (statistical) co-polymer of similar composition have been prepared. In the presence of rosin esters, these materials show... more

A novel four-arm radial block co-polymer (A-B)4 obtained by atom transfer radical polymerization (ATRP) and a random (statistical) co-polymer of similar composition have been prepared. In the presence of rosin esters, these materials show pressure-sensitive adhesive (PSA) properties. The aim of this investigation was to study the relationship between the molecular architecture of tackified systems and their typical PSA properties.

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.

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.

Most of the extraction processes of herbal phytochemicals use solvent mixtures as phytochemical transfer medium. It is very important to predict the stability of solvent mixtures before it is used to extract herbal phytochemicals. In... more

Most of the extraction processes of herbal phytochemicals use solvent mixtures as phytochemical transfer medium. It is very important to predict the stability of solvent mixtures before it is used to extract herbal phytochemicals. In order to prevent any disturbance in the herbal extraction, the solvent mixtures must be in a single-liquid phase (miscible to each other). In this study, the stabilities of five binary solvents (methanol-water, methanol-ethyl acetate, methanol-acetic acid, methanol-n-propioneldehyde, and methanol-isobutylraldehyde mixtures) that could be used in the current extraction processes are evaluated. The main purpose of this study is to evaluate these binary solvents in terms of their stability using Gibbs energy of mixing. The value of the function ∆G mix /RT is calculated for each solvent mixture. Then, the graph for ∆G mix /RT versus solvent molar fraction x is plotted. From this plot and the value of function ∆G mix /RT, it can be concluded whether the solvent mixtures is stable or unstable. From the analysis, all five binary mixtures are stable within the selected molar fraction making all mixtures are suitable to be applied in herbal extraction.

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

Blends of polypropylene copolymer (PP-cp) and a polyolefinic elastomer (POE) were prepared by a melt-blending process at 210°C and 60 rpm using a counterrotating twin-screw extruder. The POE content was varied up to 25%. The shear... more

Blends of polypropylene copolymer (PP-cp) and a polyolefinic elastomer (POE) were prepared by a melt-blending process at 210°C and 60 rpm using a counterrotating twin-screw extruder. The POE content was varied up to 25%. The shear viscosity over a wide range of shear rate was measured. All blend compositions showed well-defined zero shear viscosity and shear thinning behavior. The melt viscosity values were between those of the principal components in all cases. Rheology of blends shows different behavior up to concentrations of POE corresponding to the tough–brittle transition. The linear viscoelastic properties (G′, G″, η*, η′, η″) were used to check the miscibility of the two components in the melt state. All blend compositions showed a good degree of miscibility over the range of POE concentrations studied. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 665–671, 2002; DOI 10.1002/app.10376

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.

a b s t r a c t The miscibility of styrene-hydrogenated butadiene copolymer (SHB) with different constituents of polymer additives for lubricating mineral oils was studied in dilute solution regime, using xylene as model solvent, at 30°C,... more

a b s t r a c t The miscibility of styrene-hydrogenated butadiene copolymer (SHB) with different constituents of polymer additives for lubricating mineral oils was studied in dilute solution regime, using xylene as model solvent, at 30°C, in a wide range of polymer blend compositions. The systems studied were SHB/poly(ethylene-co-propylene) (EPC), SHB/poly (methyl methacrylate) (PMMA), SHB/poly(dodecyl methacrylate) (PDDMA) and SHB/polystyrene (PS). The viscometric interaction parameters were calculated according to the Krigbaum-Wall and Catsiff-Hewett models of ideal viscometric behavior. Strong repulsive interactions were found in SHB/PMMA and SHB/PDDMA systems pointing to immiscibility. SHB/EPC and SHB/PS deviated much less from ideality. The results were compared to the theoretical estimation of interaction in polymer blends in the absence of solvent, using the Coleman-Graf-Painter approach. No correlation was observed between the interaction in the bulk and in solution.

The effect of blending poly (styrene-co-maleic anhydride) with 14mol% MA (PSMA14) with poly (ɛ-caprolactone)(PCL) is studied by calorimetry, X-ray diffraction, dielectric techniques, and microscopy. Variations in PCL crystallization,... more

The effect of blending poly (styrene-co-maleic anhydride) with 14mol% MA (PSMA14) with poly (ɛ-caprolactone)(PCL) is studied by calorimetry, X-ray diffraction, dielectric techniques, and microscopy. Variations in PCL crystallization, melting temperatures and crystallinity ...

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.

Polystyrene nanocomposites using hybrid organic inorganic (O/I) layered double hydroxide (LDH) and 4[12-(methacryloylamino)dodecanoylamino]benzenesulfonate (MADABS) interleaved molecules were studied as a function of the filler... more

Polystyrene nanocomposites using hybrid organic inorganic (O/I) layered double hydroxide (LDH) and 4[12-(methacryloylamino)dodecanoylamino]benzenesulfonate (MADABS) interleaved molecules were studied as a function of the filler miscibility, dispersion, and the rheological behavior. Incorporation of the I/O filler gave rise to an expanded intercalated PS nanocomposite structure, while an immiscible structure was obtained after a thermal pre-treatment. However the utmost non-linear viscoelasticity in the low-ω region was obtained from the immiscible PS nanocomposite structure. Indeed, the presence of a sub-micrometer percolated structure was here depicted resulting in a jammed structure that progressively changed the typical low-frequency Newtonian flow behavior of PS to a shear-thinning behavior against the filler percentage, having as a consequence to restrict the plastic deformation in the low-ω region by obstructing polymer chain motion. From several characterizations XRD, TEM, and rheology, we demonstrated the presence of LDH agglomerates in spite of PS chain crawling in between the layers, whereas the apparent immiscible structure was composed of well dispersed LDH tactoids forming a three-dimensional percolated network. The gel-like behavior illustrated by the frequency power law dependence of the complex viscosity |η∗|∝ωn|η∗|∝ωn, n≈−0.75n≈−0.75 at 10 wt% of MADABS/LDH hybrid filler was then explained by the interconnected and concatenated hybrid LDH platelets domains developing an interfacial attrition with PS chains.Interfacial attrition developed between layered double hydroxide platelets organo-modified by monomer surfactant and polystyrene was characterized by rheology under melt polymer condition.