I. Simkovic, ONE-STEP QUATERNIZATION CROSSLINKING OF STARCH WITH 3-CHLORO-2-HYDROXYPROPYLAMMONIUM CHLORIDE/EPICHLOROHYDRIN IN THE PRESENCE OF NH4OH/, Carbohydrate polymers, 31(1-2), 1996, pp. 47-51
Quaternization/crosslinking of starch with 3-chloro-2-hydroxypropyltri
methyl-ammonium chloride (CHMAC)/epichlorohydrin (E) in the presence o
f NH4OH, NaOH and water was studied. The reaction was optimized and th
e products analyzed using solid-state NMR, acid-base titration methods
and dye-binding tests. The solid-state NMR data in the presence of wa
ter confirmed the hydroxypropyl and trimethylammoniumhydroxypropyl gro
ups in the obtained ion-exchanger. Although the linkage to starch coul
d not be proved, the CH2 groups linked to nitrogen and to oxygen could
be tentatively assigned. Optimal molar quantities and ratios are at s
tarch: E:NH4OH:NaOH:H2O:CHMAC = 0.01:0.03:0.05:0.1:0.01. The exchange
capacities (Q's) determined by potentiometric titration are smaller th
an values calculated from elemental analysis. This might be due to lon
ger equilibrium times required for the exchange of ions, than those, w
hich we could use on the automatic titrator. The dye binding propertie
s are pH-dependent for the ion-exchangers containing tertiary amine gr
oups next to quaternary ammonium groups and close to pH-independent wh
en containing only quaternary ammonium groups (prepared in absence of
NH4OH). Copyright (C) 1996 Elsevier Science Ltd.