Συντάχθηκε 15-11-2013 13:51
από Dionysia Kolokotsa
Email συντάκτη: dkolokotsa<στο>tuc.gr
Ενημερώθηκε:
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Κύρια: ΔΕΠ ΜΗΠΕΡ.
Άλλες ιδιότητες: απόφοιτος ΜΔΕ/Διδ. ΗΜΜΥ
Ερευνητικές Διαλέξεις ΠΜΣ: ΜΗΠΕΡ
Τρίτη 19/11/2013 ώρα 14:00-15:00, Αίθουσα M5002
Research Lectures of the Environmental Engineering Department
19/11/2013 14:00, Room M5002
Polymer Conformation in Single or Mixed Polar Solvents
Dr Eleftheria Antoniou
Water soluble polymers used as thickeners, stabilizers, film formers, and rheology modifiers have found great use in coatings (waterborne), personal care products, and pharmaceuticals. Over half of the coatings production is waterborne, but even "waterborne" coatings and paints are not volatile organic compound (VOC)-free, as they contain organic solvents which may comprise up to 30% of the total liquid present. Furthermore, a number of these cosolvents are classified as hazardous air pollutants (HAP). The need for both an overall VOC reduction and a replacement of HAP solvents challenges the coating and paint formulators, but the drive for reformulation is confounded by the lack of published information on the effects of cosolvents on the aqueous solution behavior of polymers and surfactants that are essential ingredients of coatings and paints. Structure-property relations between polymers and solvents are important in order to predict polymer-solvent system properties. The conformation (structure) of a common polysaccharide, dextran, as affected by solvent power, temperature and molecular weight, has been monitored in single or mixed polar solvents (water, formamide, dimethylsulfoxide, ethylene glycol) using viscosity and small angle x-ray scattering (SAXS) measurements. Dextran adopts the random coil conformation, and expands from its unperturbed dimensions depending on the solvent quality. Hydrogen bonding is the most important contributor to the solubility of dextran in the examined solvents, verified by the correlation of the polymer structure properties to the solvent properties related to hydrogen bonding.
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Antoniou_19+11_2013.pdf
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