An analytical approach to elucidate the architecture of polyethyleneimines

Polyethyleneimine (PEI) is a common polymer used in many industrial applications and research, especially surface chemistry. It available wide range of molecular weights different degrees branching. classified as linear or branched sometimes the term hyperbranched also used. This description, however, quite rough, which limits possibility to correlate structure PEI its properties. The aim this study provide analytical tools characterize at level detail not normally provided by supplier PEI. To end, five commercially polyethyleneimines were characterized Fourier transform infrared spectroscopy, thermogravimetric analysis, nuclear magnetic resonance spectroscopy gain insight into functional groups present polymers. Quantitative 13C NMR analysis turned out be particularly useful, revealing degree branching based on ratio primary, secondary, tertiary amino groups.