Polymerization and Characterization of PMMA. Polymer Chemistry Laboratory Experiments for Undergraduate Students
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Caroline Duval-Terrié [1] ; Laurent Lebrun [1]
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[1] University of Rouen
University of Rouen
Arrondissement de Rouen, Francia
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 83, Nº 3, 2006, págs. 443-446
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
This experiment gives students the opportunity to prepare polymethylmethacrylate (PMMA), one of the most important industrial polymers. Two syntheses are described, involving either free radical or anionic polymerization. The experimental conditions are flexible so that each group of students can prepare his or her own PMMA with particular properties. Various techniques for characterizing the PMMA are proposed, depending on the apparatus available in the laboratory. First, size exclusion chromatography allows students to determine the average molecular weight and polydispersity of their PMMA and to verify the kinetics scheme of the free radical polymerization. Pooling data permits students to understand the influence of the initiator:monomer ratio on the yield, molecular weight, and polydispersity of the product. Second, proton NMR spectroscopy allows students to investigate the tacticity of their polymer. Finally, differential scanning calorimetry (DSC) can be used to show the influence of tacticity on the thermal properties of the polymer. Both NMR and DSC allow students to analyze pooled data to determine the influence of experimental conditions on tacticity. The experiments are easy to perform (5 hours) and safe, provided that appropriate precautions are taken.
