Viscometric and Activation energy study of PEG 6000 in water , and solution of DMSO with water at 298.15k , 308.15 , 318.

Abstract

on the basis of viscosities of PEG 6000 in water and in mixed aqueous solution of DMSO at 298.15 ,308.15 , 318.15 k , kinematic viscosity and the Activation Energy have been calculated using Erying equation . The result are discussed in the light of Erying theory and shows that the DMSO solution preferred than water Key word Viscosity, kinematic viscosity, Activation Energy لوكيلاك ينهثا ليوب ةدالم طيشنتنا ةقاط ةساردو ةجوزهنا تاسايق 0666 ءالما في ديسكوفهسنا ميثم يئانث لوهمحو ءالما في (تاجردب 802,51.862,51.852,51 ) ةصلاخلا لوكيلاك نيمثا يلوب رميلوبمل ةجوزملا ساسا ىمع 0666 لومحم يف و, ءاملا يف تاجردب دسكوفمس ليثم يئانثل يئاملا 51.892,56.892,59.892 باسح مت كنريا ةلداعم مادختسأب طيشنتلا ةقاطو ةيكرحلا ةجوزملا 8 كنريا ةيرظن ءوض يف تشقون جئاتنلا ديسكوفمس ليثم يئانث لومحم نا ظحولو يئاملا لومحملا نم لضفا 8 Viscometric and Activation energy study of PEG 6000 in water , and solution of DMSO with water at 298.15k , 308.15 , 318. Asal Ahmed Al-Jawary Hanaa Ghali Attiya Zainab Abbas Al-Dulaimy Maida H. Saleem دلجملا ةيساسلاا ةيبرتلا ةيلك ةلجم 52 ددعلا 013 5102 38 Introduction The kinematic viscosities υ value with the concentration of PEG solution and temperature have been interpreted in accordance of the energy of interaction and frictional forces between the polymer and solvent molecules. [2] Poly ethylene glycol are synthesized by polymerization of ethylene oxide and are mercantly available over wide range of molecular weights from 300g/md to 10,000,000 g/mol very high purity PEG has latterly been appeared to be crystalline ,allowing characterization of a crystal structure by x-ray diffraction [2] PEG are liquids or low melting solids depending on their molecular weights, and have different physical properties like viscosity due to chain length effects. Chemical properties are nearly identical PEG is a polyether compound with many applications ,from industrial manufacting to medcien PEG is soluble in water, ethanol, methanol, benzen, acetonitrile, and dichlormethane, while insoluble in hexane, and diethylether. [4] In addition to hydrophobic molecules to produce non-ionic surfactants [5] Because PEG is hydrophilic molecule, it has been used to passivate microscope glass slides for avoiding non-specific sticking for proteins in single-molecule fluorescence studies. It has a low tonicity and is used in a variety of products DMSO: dimethyl sulfoxide is defined as an organo sulfur compound has formula (CH3)2 SO4. It is an important liquid Viscometric and Activation energy study of PEG 6000 in water , and solution of DMSO with water at 298.15k , 308.15 , 318. Asal Ahmed Al-Jawary Hanaa Ghali Attiya Zainab Abbas Al-Dulaimy Maida H. Saleem دلجملا ةيساسلاا ةيبرتلا ةيلك ةلجم 52 ددعلا 013 5102 39 polar aprotic solvent has colorless that miscible in a wide range of organic solvent as well as water. This is dissolved both polar and non-polar compound. DMSO has a comparatively high melting point and unusual property that many individuals sensitive agarlic -like taste in the mouth after contact with the skin [7] [8] DMSO is a polar a protic solvent and is less toxic than other kinds of this class, such as Dimethyl actamide , HMPA, and Nmethyl -2 Pyrrolidone . DMSO is extremely used as a solvent for chemical reactions involving salts, most notably. Finkelstein reactions and nucleophilic substitutions . It is also widely used as an extraction in cell biology and biochemistry . [9] [10] Because DMSO is only weakly acidic, it indulges relatively strong bases and as such has been widely used in the study of carbanions. A set of non-aqueous PKa values (C-H,O-H,S-H and N-H acidities ) Many of organic compounds have been determined in DMSO solution [11] [12] Experimental: Viscosity η was measured by using a suspended level ubbelohde viscometer with a flow time of approximately 3305 for distilled water at 298.15,303.15 and 313.15 K . thermostatic control was employed all measurements. [13] PEG 6000 available product of Aldrich chemical company USA whose number average molecular weight 6000 Kg-mol and used without any further treatment . DMSO was dimethyl Viscometric and Activation energy study of PEG 6000 in water , and solution of DMSO with water at 298.15k , 308.15 , 318. Asal Ahmed Al-Jawary Hanaa Ghali Attiya Zainab Abbas Al-Dulaimy Maida H. Saleem دلجملا ةيساسلاا ةيبرتلا ةيلك ةلجم 52 ددعلا 013 5102 40 sulfoxide (colorless liquid) was obtained from fluka company (purity > 99.7% ) and used with out any further treatment . Water used in these experiments doubly distilled ( sp – conductivity – 10 ohm cm ) . Result and Discussion: The experimental data for the molar concentration M and viscosity η and kinematic viscosity υ of PEG 6000 in water and in 2% ( DMSO with water ) at various temperatures 298.15,303.15 and 313.15 K were summarized in table 1 and table 2 The molar of solutions M was calculated applying the following relation: M= ........(1) Where M the molarity of solution mol dm M.W the molecular weight of the polymer PEG(6000 g/mol) W the weight of PEG g The calculated values of υ kinematic viscosity for all solution at different temperatures was calculated applying the following relation : υ=C t ................................(2) [15] Where C capillary viscometer constant 0.0047 t the time (second) the calculated values of υ for all solution at different temperatures were listed in table 1 table 1 showed that the values of υ increase with increase of PEG concentration and DMSO in solvent , and with elevated temperature . it indicated that the solute-solvent interaction decrease with increasing PEG concentration the activation energy of viscous flow was found by computerized least square fitting to the following equation: υ= Ae Ea RT ..................... (3) [17]