Novel cationic-modified salep as an efficient flocculating agent for settling of cement slurries

A new cationic flocculant was synthesized by graft copolymerization of acrylamide (AM) and 3-(methacryloylamino)propyl]trimethylammonium chloride (MAPTAC) onto salep using free radical polymerization initiated by ammonium persulfate (APS) to produce cationic salep [S-g-P(AM-co-MAPTAC)]. Reaction parameters (monomers/salep ratio, concentration of reactants, MAPTAC/AM ratio, and APS) were optimized using a full factorial experimental design to obtain the highest settling rate for cement suspensions. The best performing product was characterized by gel permeation chromatography (GPC), FTIR, H-1 NMR spectroscopy, and thermogravimetric analysis (TGA). The resulted cationic flocculant may be introduced as a promising candidate for the green production of asbestos-free fiber cement products by Hatschek process. (c) 2012 Elsevier Ltd. All rights reserved.