Synthesis and characterization of chitosan‐g‐methacrylic acid and studies of its additional physicochemical properties, such as swelling, metal‐ion sorption, and flocculation behavior

Abstract

The aim of this study was to examine the synthesis of a graft copolymer of chitosan and methacrylic acid (MAA) by free-radical polymerization with a potassium peroxymonosulfate/cyclohexanone (CY) redox system in an inert atmosphere. The optimum reaction conditions affording maximum grafting ratio (%G), grafting efficiency (%E), add on (%A), and conversion (%C) were determined. The grafting parameters were found to increase with increasing concentration of MAA up to 24 Â 10 À2 mol/dm 3 , but thereafter, these parameters decreased. With increasing concentration of peroxymonosulfate from 0.6 Â 10 À2 to 1.2 Â 10 À2 mol/dm 3 , %G, %A, and %E increased continuously. All of these grafting parameters increased with increasing concentration of CY up to 1.2 Â 10 À2 mol/dm 3 , but beyond this concentration, the grafting parameters decreased. With vari-ous concentrations of chitosan from 0.6 to 1.4 g/dm 3 , the maximum %G, %A, and %E were obtained at 1.4 g/dm 3 . %G, %A, and %C decreased continuously with various concentrations of hydrogen ions from 2 Â 10 À3 to 6 Â 10 À3 mol/dm 3 . The grafting parameters increased with increasing temperature up to 35 C, but thereafter, these parameters decreased. With increasing time period of reaction from 60 to 180 min, %G, %A, and %E increased up to 120 min, but thereafter, these parameters decreased. The graft copolymer was characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.

Ionic dextran derivatives for removal of Fastac 10 EC from its aqueous emulsions

“…This method has been successfully used for different type of contaminants removal (clays, dyes, surfactants, metal ion/or metal oxides, oil, etc.) (Bratskaya, Avramenko, Schwarz, & Phillipov, 2006;Cai et al, 2013;Chibowski & Wisniewska, 2001;Constantin et al, 2013;Dragan, Ghimici, Cristea, & Airinei, 1999;Ghimici & Constantin, 2011;Ghimici & Nichifor, 2013;Liimatainen, Sirvio, Sundman, Hormi, & Niinimaki, 2012;Mishra, Tripathy, Srivastava, Pandey, & Behari, 2009;Strand, Vårum, & Østgaard, 2003;Zhang, Su, Gu, Huang, & Wang, 2013). It has been also applied with good results for pesticide concentration decrease from water under some conditions (Ballard & MacKay, 2005;Latkowska & Figa, 2007;Thuy, 2008).…”

Novel biodegradable flocculanting agents based on pullulan

“…The data reported in the literature regarding the flocculation properties of the grafted copolymers reveal that the bridging mechanism plays the most important role in the separation process [12,14,20]. Furthermore, the Singh's Easy Accessibility Model (EAM) postulates the graft copolymers are more effective in the flocculation process, compared to the linear ones, because of their greater approachability to the contaminants, which could be due the spreading effect of the dangling grafted chains on the polysaccharide chains [39].…”

“…In recent years, considerable attention has been paid on the synthesis of some compounds which combine the advantages of both synthetic and natural polymers. Thus, a great number of copolymers were achieved by grafting synthetic polymers, mainly, flexible chain of poly(acrylamide) (PAM) on some polysaccaride backbone, such as gum guar, starch, konjac glucomannan, chitosan [1,[12][13][14][15][16][17][18][19][20].…”

Flocculation performance of different cationic amphiphilic dextran derivatives in zirconium silicate suspension

“…The charges on the polyions produce a strong ionic (electrostatic) field which gives them the ability to interact with their own counterions [1][2][3] as well as with charges of opposite sign belonging to suspended particles [4][5][6][7][8][9][10][11], metal ion/ or metal oxides [12][13][14][15], dyes [16][17][18], emulsions [19,20], salts [21][22][23], other (complementary) polyelectrolytes [24,25], etc. These interactions are responsible for some phenomena, such as solubilization, adsorption and subsequent separation/stabilization of different suspensions/emulsions, and surface modification, which are frequently used and exploited in water purification, pharmaceutical formulations, personal care products, foods, paint, paper, ceramic production, etc.…”