Cationic acrylamide copolymers and terpolymers as flocculants for model aqueous suspensions

Abstract

Cationic acrylamide copolymers with diallyldimethylammonium chloride and terpolymers of the both monomers with N-vinylformamide were synthesized, characterized by capillary viscometry and their flocculation efficiency evaluated by extinction, sludge volume and solid matter recovery measurements. The polymerization reactions were carried out either as thin-layer processes in aqueous solutions or as microsuspension polymerization. The results from the numerous flocculation tests performed on model aqueous suspensions of fine coal, colloidal silica and talc have been presented and discussed. Flocculation efficiency was determined taking into account the type and dose of the used copolymer. Key words: acrylamid cationic copolymers and terpolymers, diallyldimethylammonium chloride, N-vinylformamide, flocculants, flocculation efficiency. KATIONOWE KOPOLIMERY I TERPOLIMERY AKRYLOAMIDU JAKO FLOKULANTY MODELO-WYCH SUSPENSJI WODNYCHStreszczenie -Kationowe kopolimery akryloamidu z chlorkiem diallilodimetyloamoniowym oraz terpolimery tych dwóch monomerów z N-winyloformamidem (schemat A) otrzymywano dwoma metodami: w cienkiej warstwie roztworu wodnego b¹dŸ w postaci mikrosuspensji (tabela 1). Scharakteryzowano je metodami wiskozymetrii kapilarnej (tabela 2) a tak¿e oceniono ich efektywnooeae floku-lacyjn¹ na drodze pomiaru ekstynkcji oraz objêtooeci i masy osadu poflokulacyjnego. Przedstawiono i przedyskutowano wyniki licznych testów flokulacyjnych przeprowadzonych na modelowych wodnych zawiesinach mia³u wêglowego (tabela 3, rys. 1), krzemionki koloidalnej (tabela 4, rys. 2) oraz talku (tabela 5, rys. 3). Efektywnooeae flokulacyjn¹ porównywano uwzglêdniaj¹c typ i dawkê u¿ytego flokulantu. S³owa

A new method of spectrophotometric determination of poly(diallyldimethylammonium chloride) concentration

“…The vis spectra of mixtures of PDDA with the Bradford reagent, presented in Figure 1, proved that the CBB dye and PDDA form a complex (CBB-PDDA) having extinction coefficient value from 48000 to 21000 dm 3 •mol -1 •cm -1 . Absorbance of the CBB-PDDA complex depends on the concentration of polymer monomer units.…”

“…Poly(diallyldimethylammonium chloride) (PDDA) of average molecular mass of 100-200 kg/mole has been obtained from Aldrich as a 20 % water solution with density of 1.04 g/cm 3 . The stock solution of PDDA with concentration of 0.322 mmole(mer)/dm 3 has been prepared by diluting the basic solution with distilled water and stored in the dark.…”

“…The stock solution of PDDA with concentration of 0.322 mmole(mer)/dm 3 has been prepared by diluting the basic solution with distilled water and stored in the dark. The sample solutions have been prepared in volumetric flasks, taking 10 cm 3 of the Bradford reagent, adequate quantity of the stock solution and distilled water up to the volume of 50 cm 3 . Preliminary measurements proved that samples prepared in the described way are stable for 20 min.…”

“…PDDA applied in wastewater treatment causes neutralization of negatively charged colloidal particles [1,2]. Both PDDA and diallyldimethylammonium chloride copolymers may be also used in water clarification processes to remove mineral suspension particles, algae and humic substances [3][4][5]. However, while applying PDDA care should be taken, because it is not neutral for the human health.…”

On some aspects concerning solution-suspension polymerization of N-vinylformamide

“…The chemical properties and non-toxicity of PNFV and PVAm resulted in a broad range of industrial applications such as paper making [16][17][18], adhesives [19,20], ink jet printing [21], textile chemicals [22], biomedical products [23,24], flocculants [25] etc. That reflects the importance these polymers have already gained.…”