Water‐soluble acrylamide copolymers: V. Dispersion properties of poly(acrylamide‐co‐ p ‐maleimidobenzoic acid) and poly(acrylamide‐co‐sodium N , N ‐diallylsulfanilate)

Eight new poly(acrylamide‐co‐p‐maleimidobenzoic acid) (PAMMBA) water‐soluble copolymers, 3 , have been prepared in a synthetic study with the objective to determine the influence of ring incorporation on the surface activity of these materials. 1 Sufficient sample was obtained from three of these experiments to enable measurement of the dispersion properties of these polymers using aqueous kaolinite suspensions. PAMMBA‐1, ‐2, and ‐3 copolymers containing 7, 13, and 23 mole percent p ‐maleimidobenzoic acid (MBA) were tested. Their effectiveness as dispersants increased with increasing MBA content. But the copolymer containing 23% MBA required a dose rate four to eight times that of DISPEX N‐40, a commercial dispersant, to obtain equivalent dispersion properties from a standard kaolinite suspension. In similar copolymer synthesis experiments, ten new poly(acrylamide‐co‐sodium N,N ‐diallylsulfanilate) (PAMDAS) copolymers were also prepared and fully characterized. 2 Sufficient material was isolated from three of these preparations to enable testing of the dispersant activity. PAMDAS‐1, ‐2, ‐3 copolymers contained 3·0, 8·4, and 19·2 mole percent sodium N,N ‐diallysulfanilate (DAS) and were tested as dispersants in experiments conducted so as to produce results comparable to those of both the PAMMBA copolymers and a commercial dispersant. Dispersant effectiveness increased with increasing DAS content. PAMDAS‐1 (3·0% DAS) was about the same effectiveness as PAMMBA‐1 (7% MBA), PAMDAS‐2 (8·4% DAS) was more effective than PAMMBA‐2 (13% MBA), and PAMDAS‐3 (19·2% DAS) was about equivalent in effectiveness to PAMBA‐3 (23% MBA). Relative to DISPEX N‐40, however, PAMDAS‐2, at a dose rate of 2000 ppm by weight was about half as effective as DISPEX N‐40 at a 250 ppm dose rate.