Acrylic Cws Additives

In this study, using acrylic acid (AA), methyacrylate (MA), acrylamide (AM) as monomers of copolymerization , ammonium persulfate and sodium bisulfite as redox system initiator, iso-propanol as chain transfer agent, random copolymers of P(AA-MA)and P(AA-MA-AM) are synthesized by means of aqueous solution copolymerization .The composition, structure, surface tension, glass transition, and thermal weight loss of copolymers are characterized by FT-IR, surface tension-meter and DSC-TG .Using orthogonal experiment, the polymerization conditions are optimized, the influence extents and trends of which on the intrinsic viscosity of copolymers are studied.Copolymers as additives of CWS are studied, the slurry-abilities of which in the CWS are investigated .The optimal dosages of copolymers and the maximal concentrations of CWS are given. Therefore, the optimal conditions of copolymerization are given. The optimal conditions of binary polymerization are molar ratio of monomers (AA:AM) 8:1, time of reaction 2.5h, temperature of reaction 60℃, dosage of ammonium persulfate 2%, dosage of sodium bisulfite 6%. The optimal conditions of terpolymerization are molar ratio of monomers (AA:AM:MA) 4: 1: 1, time of reaction 3h, temperature of reaction 80℃, dosage of ammonium persulfate 5%, dosage of sodium bisulfite 4%.Based on the analysis of XPS, TEM and FT-IR, the results show that copolymers are adsorbed effectively on the surface of coal particles ,their hydrophilicity is improved , thus interface properties of coal-water system are improved ,which makes CWS more stable and dispersible.