NMR 13C study of the structure of polyethyleneimine

✍ Scribed by G.M. Lukovkin; V.S. Pshezhetsky; G.A. Murtazaeva

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 398 KB
• Volume: 9
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(73)90039-6

✦ Synopsis

Al~lraet--The NMR 13C (CMR) spectrum of high molecular weight (M = 20,000) branched polyethyleneimine (PEI) obtained by polymerization of ethyleneimine (EI) in aqueous and alcoholic solutions at 50 ° with 1,3-dichloropropanol as initiator, contains 8 lines. The lines were identified using CMR spectra of model compounds, i.e. linear PEI, regularly branched PEI, diethylenetriamine and ethyleneimine pentamer. It has been shown that the deshielding effect of the nitrogen atoms on the a-atoms of carbon decreases in the folowing order: Ntert > N~c > Nprlm; with the atoms of carbon in the E-position, the effect increases in the opposite order.

A quantitative estimation has been made of the distribution of the diads of elementary units containing the same and different nitrogen atoms. The data have been used to draw some conclusions about the structure of the PEI macromolecule. * All the PEI and oligomer samples of different structures were kindly given by Professor D. S. Zhuck of the Institute of Oil and Chemical Synthesis of the USSR Academy of Sciences. 559 Acknowledgement--We are grateful to our colleagues P. A. Gembitsky and V. N. Andronov for samples and helpful discussion.