Solid-State NMR and termal analysis in copper polymer complexes

JUAN MANUEL LÁZARO MARTÍNEZ; LEAL DENIS MARÍA FLORENCIA; DENADAY, LR; GRACIELA YOLANDA BULDAIN; VIVIANA CAMPO DALL ORTO

Mainz

Simposio; Frontiers in Polymer Science – International Symposium Celebrating the 50th Anniversary of the Journal Polymer; 2009

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Two particular interesting groups of functionalized polymeric materials are the polyampholytes and polyelectrolytes [1-4]. We have recently syntethized new polymeric materials with the characteristics of polyelectrolyte (Poly(EGDE-MAA) = A) or polyampholyte (Poly(EGDE-MAA-IM) = B) and their copper(II) complexes, respectively [5-7]. Remarkably, the Cu(II)-polyampholyte acts as an efficient heterogeneous catalyst for H2O2 activation and the degradation of Methyl Orange [8]. The coordination behavior of the carboxylic acid of the MAA, compared to that provided by the imidazole ring, was studied through solid-state NMR and changes in the FTIR spectra. It was possible to observe that the carbon signal of the carboxylic acid disappeared in the A and B materials in the 13C CP-MAS spectra at 1 and 63 mg of Cu(II) per gram of material, respectively, in agreement with the FTIR results [7]. In the B complexes, a competence for the complexation through imidazole and MAA occurs; then, when the imidazole is saturated, the complexation takes place preferentially through MAA, as concluded from the FTIR and solid-state NMR results. However, the DSC studies determined the presence of different molecular mobility regions within both A and B polymers, in agreement with the double decay observed in the experiments. On the other hand, the 2D WISE-NMR experiments together with the relaxation experiments allow us to conclude that although the relaxation behavior was modified, the paramagnetic ion does not change the structure of the polymer substantially [7].