Lactic acid based aliphatic polyesters are being increasingly explored for use in applications such as biodegradable packaging materials, food containers, bioresorbable medical implants and sutures, drug delivery systems, etc. Lactic acid possesses one asymmetric carbon and exists in two configurations, R and S. A number of physical properties of polylactide (PLA) are linked to its stereosequence distribution. The stereosequence distribution is influenced by a number of factors including the starting lactide feed composition, polymerisation kinetics, and extent of conversion. The polymerisation kinetics are, in turn, influenced by the catalyst, temperature, impurities, batch vs. continuous process, etc. Solution and solid-state NMR spectroscopy is used to examine important features of PLA such as polymerisation kinetics, polymer tacticity and solid-state morphology. The 1H and 13C NMR spectra of PLA in solution provides information about the sequence of the lactic acid units because of the relationship between the stereogenic centres and their influence on the chemical shift. In the solid state, the 13C NMR spectra provide information about polymer morphology and crystal structure. 15 refs.
CITATION STYLE
Zell, M. T., Padden, B. E., Paerick, A. J., Hillmyer, M. A., Munson, E. J., Thakur, K. A. M., … ACS, Div. of P. M. S. & Engng. (1998). Characterisation of Polylactide using Solution and Solid-State Nmr Spectroscopy. In ACS Polymeric Materials Science & Engineering, Spring Meeting 1998. Volume 78. (pp. 137–138).
Mendeley helps you to discover research relevant for your work.