Spin-label study of immiscible polymers: 5. Blends of labelled poly(2-ethyl hexyl methacrylate) with poly(methyl methacrylate) and polystyrene
| Autor: | G. Gordon Cameron, Richard Buscall, David Stewart, J. Nemcek, M.Y. Qureshi |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
chemistry.chemical_classification
Nitroxide mediated radical polymerization Materials science Polymers and Plastics Organic Chemistry Polymer Poly(methyl methacrylate) chemistry.chemical_compound End-group chemistry visual_art Polymer chemistry Materials Chemistry visual_art.visual_art_medium Polystyrene Methyl methacrylate Glass transition Spin label |
| Zdroj: | Polymer. 36:3071-3074 |
| ISSN: | 0032-3861 |
| DOI: | 10.1016/0032-3861(95)97867-f |
| Popis: | The electron spin resonance (e.s.r.) spectra of poly(2-ethyl hexyl methacrylate) (PEHMA) spin-labelled with nitroxide end groups were recorded over a temperature range for both the pure, bulk polymer and for 1 : 1 (w/w) immiscible blends with poly(methyl methacrylate) (PMMA) and polystyrene (PS). Both PMMA and PS have significantly higher glass transition temperatures than PEHMA, with which they are immiscible. Nevertheless, the glassy component of these blends exerts a retarding effect on the motion of a portion of the spin labels on the PEHMA, as evidenced by the presence of a persistent slow-motion component in the e.s.r. spectra of the blends. These experiments complement our earlier work in which the spin label was attached to the chain ends of the glassy component in a binary blend. The results support our previous conclusion that in a blend of two immiscible polymers, chain ends tend to congregate in the interphase where they experience the combined influences of accumulated free volume and the presence of the other polymer. |
| Databáze: | OpenAIRE |
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