Investigation of the protonation of triethylenetetramine by means of a glass electrode

Factors affecting the sampling of poly(ethyleneimines) by electrohydrodynamic mass spectrometry

“…Furthermore, the intensity of the sodiated series did not change appreciably (Table III); deprotonation apparently did not greatly increase the amount of polymer available for sodiation. The implication that multiple protonation was not extensive even prior to addition of NaOH is reasonable; even in the unlikely event that all p.Kbs of polybasic PEI 1800 are as low as 3.87 (the smallest aqueous p-iQ, of TETA (34), the extent of double protonation in water would be small (<7%, even allowing for protonation by residual acid catalyst from the polymerization (33)). Because glycerol is a poorer proton donor than water (the pK& of glycerol is 14.1 ( 35)), protonation in this solvent would be even less extensive.…”