Synthesis of a Biodegradable PLA: NMR Signal Deconvolution and End-Group Analysis

Abstract

NMR spectroscopy is a powerful spectroscopic tool that not only allows the determination of structures after synthesis, as usually explained to students of Organic Chemistry, but also is useful in many other fields such as medicine imaging, real-time industrial processes, material sciences, or metabolomics. In this experiment, students performed a ring-opening polymerization (ROP) reaction in the laboratory and, then, collected a series of 1D NMR spectra with the aim of determining the tacticity of the polymers formed and their number-average molecular weight. The deconvolution of 1H and 13C NMR experimental data was central in their learning process, and the consistence of the results obtained was validated within the literature. This exercise gave students skills on polymerization reaction processes, instrumental analysis, and determination and interpretation of NMR spectra in the use of deconvolution procedures along with the critical evaluation of the obtained results.