Polymer-solvent interactions in thermoreversible gels of isotactic poly(methyl methacrylate) as studied by measurement of 1h NMR relaxation of the solvent |
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Authors: | Jiř i Spê vá č ek,Jiř i Brus |
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Abstract: | Dynamic structure and polymer-solvent interactions in solutions and gels of isotactic (i) poly(methyl methacrylate) (PMMA) in butyl acetate (BAC) were characterized by measurements of nonselective and selective 1H NMR spin-lattice relaxation times of the solvent. In thermoreversible gels, the existence of i-PMMA-BAC complex, where the life-time of the bound solvent is − 100 ms or shorter, was confirmed. Although the correlation time of the solvent bound in i-PMMA-BAC complex is 5-10 times longer than for the free solvent, there is still a relative motional freedom for complexed solvent molecules. The same behaviour observed recently for thermoreversible gels of syndiotactic PMMA indicates the same character of polymer-solvent complexes in gels of both stereoregular forms of PMMA. |
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