Small-angle neutron scattering and differential scanning calorimetry study of associative behaviour of branched poly(ethylene oxide)/poly(propylene oxide) copolymer in aqueous solution
Autor: | A. Sikora, Alexander I. Kuklin, I. Krakovský, H. Pospíšil, Josef Pleštil |
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Rok vydání: | 2003 |
Předmět: |
Ethylene oxide
technology industry and agriculture Oxide Concentration effect Neutron scattering Small-angle neutron scattering Micelle General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound Differential scanning calorimetry chemistry Polymer chemistry Physical chemistry Propylene oxide |
Zdroj: | Journal of Applied Crystallography. 36:970-975 |
ISSN: | 0021-8898 |
Popis: | Tetronic RED 9040, a reverse-type [poly(propylene oxide) as terminal blocks] octablock star copolymer with four poly(ethylene oxide)/poly(propylene oxide) arms attached to the ethylenediamine core was studied in D2O at concentrations between 1 and 60 g dL−1in the temperature range from 283 to 353 K. Depending on concentration and temperature, various structures (unimers, random network, micelles, micellar aggregates, micellar networks) were indicated by small-angle neutron scattering (SANS). Some structure characteristics of unimers, micelles and micellar networks have been determined by fitting model scattering functions to the SANS data. A competition between the increasing association number and dehydration of the micelles is suggested as a possible explanation of the observed non-monotonic temperature dependence of the structure parameters of concentrated systems. A partial phase diagram was suggested on the basis of SANS and differential scanning calorimetry (DSC) data and visual inspection of the solutions. |
Databáze: | OpenAIRE |
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