Thermoresponsive Properties of Poly(N-vinylcaprolactam)-Poly(ethylene oxide) Aqueous Systems: Solutions and Block Copolymer Networks
| Autor: | Natalya A. Yanul, Sam Verbrugghe, Yury E. Kirsh, Filip Du Prez, Eric J. Goethals |
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| Rok vydání: | 2001 |
| Předmět: |
Materials science
Aqueous solution Polymers and Plastics Ethylene oxide Hydrogen bond Organic Chemistry Oxide Concentration effect Condensed Matter Physics chemistry.chemical_compound chemistry Phase (matter) Polymer chemistry Materials Chemistry Copolymer Physical and Theoretical Chemistry Glass transition |
| Zdroj: | Macromolecular Chemistry and Physics. 202:1700-1709 |
| ISSN: | 1521-3935 1022-1352 |
| DOI: | 10.1002/1521-3935(20010601)202:9<1700::aid-macp1700>3.0.co;2-f |
| Popis: | Two- and three-dimensional phase diagrams have been constructed for thermosensitive poly(N-vinyl-caprolactam)-poly(ethylene oxide) (PVCL-PEO) aqueous systems. Both solutions and swollen block copolymer networks have been investigated to elucidate the effect of th copolymer content and crosslinking density on their temperatures of phase separation (T ph.s ). The introduction of hydrophilic PEO into an aqueous solution of PVCL decreases its T ph.s . This suggests that the strength of the hydrogen bonds within the thermoresponsive PVCL-water system is weakened by the introduction of PEO that also interacts with water. Based on the DSC investigation the swollen networks, it was found that the influence of PEO on the phase behavior of weakly crosslinked networks is comparable with that of PVCL-PEO-H 2 O solutions. For networks with a higher degree of crosslinking, the presence of the crosslinks is of major importance for the explanation of the T phs location. This detailed phase analysis led to the proposal of an irregular water distribution in these swollen networks. |
| Databáze: | OpenAIRE |
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