Linear polyethylene imine prepn. - by mass polymerise. at higher and lower temps. in presence of cationic catalyst

摘要

Linear polyethyleneimine is prepd. by (a) polymerising ethyleneimine and its oligomers dimers, trimers and/or linear tetramers at 40-55 degrees C in the presence of 0.1-1.0 mole % mineral acid, ammonium salt of a mineral acid, dichloropropane or dichloropropanol as catalyst, per 1 elementary unit of ethyleneimine, until 10-25% of the ethyleneimine rings have been converted. (b) cooling the polymn. mixt to 5-25 degrees C (c) adding water to the cooled polymn. mixt. the wt. ratio of added water to mixt. being 1:2.5-2.5:1 (d) hodling the mixt. at 5-25 degrees C until the end of polymn. to form a heterogenous polymn. mixt. contg. the crystalline hydrate of the lnear polyethyleneimine in the form of a precipitate, (e) separating the precipitate from the polymn. mixt. and (f) drying the precipitate at 50-100 degrees C under vacuum.