Comparative Study of Solvation Behaviour of Oxidising Agents Like Kclo3, Kbro3 and KIO3 in Aqueous Solvent Systems at Different Temperatures

The investigation of the solvationtrend of oxidizing agents like KClO3, KBrO3 and KIO3as electrolytes in aqueous salt solution rendersthe datasuited to interpret ion–ion, solute–solvent, ion-solvent and solvent–solvent interactions and synergy. Apparent molar volumes (∅_V) and viscosity B-coefficients for KClO3, KBrO3 and KIO3solutions in aqueous 0.5 % KCl ,system have been calculated from density (ρ) and viscosity (η) measurements at 298.15 to 313.15 K using a calibrated bicapillary pycnometer and the simple, yet accurate apparatus known as Ubbelohde viscometer respectively. Jones-Dole equation,Masson’s equation, Roots equation and Moulik’s equations are implemented to analyse various interactions inter and intra ionic attractions among the ion–ion, ion–solvent, and solute–solvent. Additionallythe apparent molar volumes of transfer Δ ∅(tr) and Rate constant diffusion controlled reaction (kd)are valuated.

Synthesis of Propylene Oxide – Styrene Copolymers

The copolymerization of propylene oxide (PO) with styrene (St) catalyzed by Maghnite-H+ (Mag-H+) was investigated. Mag-H+, a nontoxic catalyst for cationic polymerization of vinylic and heterocyclic monomers, is a montmorillonite silicate sheet clay. This catalyst was prepared through a straight forward proton exchange process. It was found that Mag-H+ initiates the copolymerization in bulk at room temperature. Various techniques, including H1NMR, 13C-NMR, FT-IR spectroscopy, and Ubbelohde viscometer, were used to elucidate the resulting copolymers' structural characteristics. The effects of the amount of Mag-H+ and propylene oxide were studied. The yield of copolymerization depends on the amount of Mag-H+ used and the reaction time.

Glycerin/NaOH Aqueous Solution as a Green Solvent System for Dissolution of Cellulose

Dissolving cellulose in water-based green solvent systems is highly desired for further industrial applications. The green solvent glycerin—which contains hydrogen-bonding acceptors—was used together with NaOH and water to dissolve cellulose. This mixed aqueous solution of NaOH and glycerin was employed as the new green solvent system for three celluloses with different degree of polymerization. FTIR (Fourier-transform infrared), XRD (X-ray diffractometer) and TGA (thermogravimetric analysis) were used to characterize the difference between cellulose before and after regenerated by HCl. A UbbeloHde viscometer was used to measure the molecule weight of three different kinds of cellulose with the polymerization degree of 550, 600 and 1120. This solvent system is useful to dissolve cellulose with averaged molecule weight up to 2.08 × 105 g/mol.

Viscosity, Miscibility Studies and Mechanical Properties of Pullulan/Poly(vinyl alcohol) Blends at 30 ºC and 40 ºC

The miscibility studies of pullulan and poly(vinyl alcohol) (PVA) blends by reduced viscosity measurements, refractometry, mechanical properties and SEM analysis. Viscometric measurements at 30 and 40 ºC were taken using Ubbelohde viscometer. Ultrasonic interferometric was used to measure the ultrasonic velocities of different blend compositions. Refractive indices of blend solutions with different compositions were measured directly with an Abbe′s refractometer with thermostat containing water circulated at 30 and 40 ºC. The mechanical properties, refractive index, ultrasonic velocity and density studies showed that there is an increase of all these with PVA content in the blends. But SEM studies have given an indication of immiscibility in the blend system. Overall, pullulan/PVA blends have shown good physical and mechanical properties particularly for 90/10 composition.

An alternative and indirect statistical modeling method for viscosity estimation and its experimental validation for low styrene content polyester resin

We propose an indirect method of ASTM D-1200 for measurement of viscosity from 0.1 to 30 stokes (St) using Ford cup 5 (range 2~ 12 St) by developing a statistical relation. General purpose low styrene content polyester resin (without adding initiator, hardener and accelerator) was used for viscosity measurement. In existing ASTM D 1200 standard, ford cups (1-4) are used to measure the viscosity up to 2 St, while fifth cup is used for measurement from 2 to 12 St. Viscosity above 12 St is not estimated using existing ASTM D- 1200 method. In contrast, our method and statistical relation proposed in this paper estimates viscosity in the flexible range of 0.1 to 30 St by using Ford cup 5 only. The estimated values were confirmed by existing ASTM D-1200 (0.1 to 12 St) and by using Ubbelohde viscometer (12 to 30 St). Values estimated above 12 St are from the proposed model are also in good conformance (percentage error ~ 5% or less) with experimental results. The satisfaction level of the estimated values with the experiments suggests that the model has also the potential for application to paints, polymer and oil industry.

Salt effects on the dilute solution properties of bototo gum (Cochlospermum vitifolium)

<p><span style="line-height: 113%; font-family: 'Times New Roman',serif; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 14.0pt; mso-contextual-alternates: yes; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Salt effects on the dilute solution properties of bototo gum (<em>Cochlospermum vitifolium</em>) were investigated. There were measured the intrinsic viscosities of the polymer under study in water, in NaCl (at different concentrations) and in NaCl, CaCl₂ and AlCl₃, at the same ionic strength (I = 1), using an Ubbelohde viscometer at 25°C. The Huggins intersection model (R²) is more appropriate to determine the intrinsic viscosity than the Kraemer's equation. This parameter tends to reduce with the increase in the salt concentration and the cation charge. The molecules of <em>C. vitifolium</em> gum exudate in water (solvent Φ) tend to adopt a “random coil” conformation, of great volume and radius, which exist in two regimes: diluted and semi-diluted; in the presence of salts, the coils exist only in a diluted regime where they are separate each other. The macromolecules in water have probably an extended ellipsoid shape but in presence of salts, they change to another more compact, probably spherical, with radii and smaller volumes. The knowledge of the behavior of <em>C. vitifolium</em> gum molecules in dilute solutions is an important criterion for its rational use in various industries</span></p>

Solubility and solubilizing capabilities of aqueous solutions of Extractum Taraxaci e radix cum herba aqu. siccum in light of selected values of general Hildebrand-Scatchard-Fedors theory of solubility

Summary Introduction: The general Hildebrand-Scatchard theory of solubility supplemented by Fedors’ solubility parameter $- \delta ^{{1 \over 2}} $ was used to estimate the real solubility by −log x2 (log of the mole fraction) of phytochemicals contained in Ext. Taraxaci e radix cum herba aqu. siccum. Surface activity of aqueous solution of extracts was determined and quantified – solubilizing capabilities of solutions of cexp. ≥cmc in relation to cholesterol particle size of Ø=1.00 mm, as well as of ketoprofen were defined. Objective: The calculated value −log x2 collated with the polarity of extraction medium εM allows to estimate the optimal solubility of phytochemicals that determine the viscosity of the aqueous extract of dandelion and above all its surface activity and the ability to solubilize lipophilic therapeutic agents (ketoprofen). Methods: Viscosity of water model solutions of dandelion extracts and exhibition solutions after the effective micellar solubilization of cholesterol and ketoprofen was measured using Ubbelohde viscometer in accordance with the Polish Standard. The surface tension of aqueous solutions of extract and exhibition solutions after solubilization of cholesterol and ketoprofen was measured according to the Polish Standard with stalagmometric method. Results: The calculated factual solubility, and mainly the determined and calculated hydrodynamic size mean, that despite the complex structure of the micelle, it solubilizes cholesterol (granulometric grain of diameter Ø=1.00 mm) and ketoprofen (state of technological fragmentation) in equilibrium conditions. Equilibrium solubilization of ketoprofen also occurs in an environment of model gastric juice (0.1 mol HCl). Conclusions: The obtained results indicate that after the administration (and/or dietary supplementation) with Ext. Taraxaci e radix cum herba aqu. siccum, the physiological parameters of gastric juice would not be measured and its presence (phytosurfactant) in the body of the duodenum (bile A) increases abilities of solubilizing lipophilic therapeutic agents and cholesterol accounting for its use in the treatment of liver diseases and cholesterol gall bladder stones.

Synthesis and Salt Resistance of Novel Polyampholyte P(DMAPMA-co-HEA)-CA

A novel polyampholyte P(DMAPMA-co-HEA)-CA was prepared by the quaternization of chloroacetic acid (CA) to P(DMAPMA-co-HEA), which was synthesized by the copolymerization of 2-hydroxyethyl acrylate (HEA) and N-(3-dimethylaminopropyl)maleamic acid (DMAPMA). The isoelectric point (IEP) of P(DMAPMA-co-HEA)-CA was studied by titration, and the salt resistance of P(DMAPMA-co-HEA)-CA expressed by viscosity was determined in sodium chloride solution by Ubbelohde viscometer. The results show that P(DMAPMA-co-HEA)-CA possesses excellent salt resistance in sodium chloride solution.

Effect of liquid butadiene rubber on mechanical properties of polyamide 11/polyamide 12 blends

Polyamide 11 (PA 11)/polyamide 12 (PA 12) blends with and without liquid polybutadiene (LB) containing isocyanate end groups (LBD) were prepared in the Brabender plastograph. The rubber was added in order to increase the impact strength of the polyamides. Tensile strength and elongation at the upper yield point and hardness were also measured. Thermal properties were determined by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Fourier transform infrared (FTIR) spectroscopy was used to determine functional groups of polyamides and to reveal possible reactions between the polyamides and LBD. Intrinsic viscosity, measured by an Ubbelohde viscometer, was used to calculate molar mass. The LB has been found as a useful modifier of impact strength.

Relationship between intrinsic viscosity, thermal and retrogradation properties of amylose and amylopectin

The relationships between intrinsic viscosity and some properties of amylose and amylopectin were investigated. The intrinsic viscosities determined by Ubbelohde viscometer for rice, maize, wrinkled pea and potato amyloses were 46.28 &plusmn; 0.30, 123.94 &plusmn; 0.62, 136.82 &plusmn; 0.70, and 167.00 &plusmn; 1.10 ml/g, respectively; and the intrinsic viscosities of rice, maize, wrinkled pea and potato amylopectins were 77.28 &plusmn; 0.90, 154.50 &plusmn; 1.10, 162.56 &plusmn; 1.20 and 178.00 &plusmn; 1.00 ml/g, respectively. The thermal and retrogradation properties of amylose and amylopectin were investigated by differential scanning calorimeter (DSC). Results showed that the thermal enthalpy (&Delta;H_g) was positively correlated with intrinsic viscosity, however, the onset and peak temperatures were not related to the intrinsic viscosity. The amylose and amylopectin retrogradation enthalpy values were negatively related to intrinsic viscosity, while the onset and peak temperature values of retrograded amylose and amylopectin were not related to the intrinsic viscosity during storage (except one-day storage). Furthermore, the onset and peak temperatures and retrogradation enthalpy of amylose and amylopectin changed slowly during storage at 4&deg;C. &nbsp; &nbsp;