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, (1)H 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.