Thermal Decomposition Behavior of a Chelating Resin Immobilizing Carboxymethylated Polyethyleneimine: Possibility of Estimation of Carboxymethylation Rate.

Chelating resins immobilizing carboxymethylated polyethyleneimine (CM-PEI) with different carboxymethylation rates were prepared. The thermal decomposition behavior of CM-PEI resins was investigated using thermogravimetry-differential thermal analysis/photo ionization-quadrupole mass spectrometry (TG-DTA/PI-QMS) and ion attachment ionization-quadrupole mass spectrometry equipped with direct inlet probe (DIP/IA-QMS). The obtained results suggested that the carboxymethyl group decomposed at relatively low temperature (150 °C - 300 °C); the peak areas at m/z 45 and 59 in TG-DTA/PI-QMS and m/z 58, 70, and 72 in DIP/IA-QMS significantly increased with increasing carboxymethylation rate. These relationships should be useful for estimating the carboxymethylation rate of CM-PEI resin.