Applications of Labelling and Multidimensional NMR in the Characterization of Synthetic Polymers

Abstract

Publisher Summary This chapter discusses some of the recent developments in the application of high resolution 1D and 2D nuclear magnetic resonance (NMR) to synthetic polymers formed by chain polymerization, paying particular attention to the advances made, with the use of polymers prepared with specifically labeled initiators or monomers. The physical and mechanical properties of the synthetic polymers, formed by chain polymerization, depend critically on the arrangement and relative configuration of monomer units within the chains. The chapter discusses the tacticity of homopolymers and monomer sequence distribution of copolymers prepared from 1- or 1,l-disubstituted olefins. The syntheses of many of the monomers, commonly used in chain polymerizations that are specifically 13 C-labelled, are summarized in this chapter. It is noted that the synthesis of carbon-14 labeled monomers can usually be readily adapted to the synthesis of the corresponding 13 C-labelled compounds. Various methods are utilized for the determination of the polymer end groups. These include: chemical analysis, various forms of spectroscopy (UV, IR, and NMR), pyrolysis- gas chromatography, and radioisotope labeling. The methods for the determination of initiator-derived ends can be divided into two categories: (a) those that involve direct determination of the polymer end-groups; and (b) those that involve the use of an initiator that is specifically labeled to aid the detection of derived end groups.