Water-soluble acrylamide copolymers containing succinimide or pyrrolidine rings
Date
1989
Authors
Syme, David Thomas
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Abstract
Acrylamide copolymers containing succinimide or pyrrolidine rings in the polymer backbone were prepared to determine if the bridging ability of polyacrylamide flocculants could be improved by stiffening the polymer chains. The five-membered rings were introduced by the free radical copolymerization of acrylamide with sodium N-(4-sulfophenyl)maleimide, p-maleimidobenzoic acid, sodium N,N-diallylsulfanilate, and N,N-diallylaniline. All of the copolymers were characterized by elemental analysis, photoacoustic FTIR, 13c NMR, gel permeation chromatography, and viscometry. In addition, sufficient data were obtained for the copolymerization of acrylamide with sodium N-(4-sulfophenyl)maleimide to calculate reactivity ratios for that system.
Poly(acrylamide-co-sodium N-(4-sulfophenyl)maleimide) performed poorly compared to commercial partially hydrolyzed polyacrylamides (HPAM), when used to flocculate a 3% Camontmorillonite suspension at pH 4.0 and pH 7.5. Poly(acrylamide-co-sodium N-(4-sulfophenyl)malemide), poly(acrylamide-co-p-maleimidobenzoic acid), and poly(acrylamide-co-sodium N,N-diallylsulfanilate) behaved as dispersants instead of flocculants, when tested on a 3% kaolinite suspension at pH 4.6. The molecular weights of the copolymers were too low for polymer bridging between the clay particles to occur. Although the copolymers were reasonably effective dispersants, they were not as effective as a commercial polyacrylate dispersant unless used at dosages at least four times higher than that of the commercial dispersant.
Poly(acrylamide-co-N,N-diallylaniline) was not sufficiently water-soluble to be useful as a flocculant. It was concluded from the results of the polymerization and flocculation experiments that effective high molecular weight anionic flocculants can not be prepared by the copolymerization of acrylamide with maleimide or diallyl monomers. The copolymerization rates of maleimide and diallyl monomers are too low.