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US 4,357,464 AGranted
Removal of 2-isopropenyl-2-oxazoline monomer
AssigneeThe Dow Chemical Company
InventorsDonald A. Tomalia, Timothy J. Adaway
Life of this patent
Estimating the term…
Abstract
The level of residual 2-isopropenyl-2-oxazoline monomer in polymers prepared therefrom can be reduced by reaction of the protonated salt of the monomer with a variety of nucleophiles. The products of the reaction with the monomer are much less toxic than the 2-isopropenyl-2-oxazoline and the utility of the polymer is thereby enhanced. The reaction product of 2-isopropenyl-2-oxazoline and H.sub.2 SO.sub.3 is itself novel and useful.
Claims8
A process for reducing the level of 2-isopropenyl-2-oxazoline present in a polymer comprising the steps of:
- (a) contacting at reactive conditions in a liquid medium the polymer containing the 2-isopropenyl-2-oxazoline with a protic acid, H-X, so as to produce the corresponding 2-isopropenyl-2-oxazolinium salt of the conjugate base of the acid;
- and
- (b) contacting at reactive conditions the 2-isopropenyl-2-oxazolinium salt with a nucleophilic compound, H-M having a nucleophilic constant of greater than 5, so as to prepare a compound corresponding to formula I or formula II ##STR9## wherein M is the conjugate base of the nucleophilic compound H-M and X in Formula II is an anion derived from the protic acid.
Dependencies are inferred from the claim text.