Synthesis Of Amphiphilic Copolymers Dispersants And Their Effect On Rheological Behavior Of Polystyrene Latex And Coal Water Slurry

With rapid development of society and economic, energy consumption also increased dramatically in our country. Coal resources accounts for a high proportion in our energy production and consumption. Coal water slurry(CWS) has come to the limelight as an alternative choice for oil due to its high combustion. To improve rheological property and stability of CWS, dispersants with certain structure are needed.In this paper, amphiphilic poly(styrene-co-maleic anhydride naphthylamide sulfonate)s (SMANS) were synthesized. To explore the mechanism to improve the CWS rheological property of these copolymers, polystyrene (PS) latexe with narrow size distribution were synthesized and employed as model CWS. Effect of particle size, concentration and SMANS on rheological behavior of PS latex were invested. Viscosity of PS latex increased with the decrease of particle size and increase of concentration. Upon the addition of SMANS, viscosity of PS latex reduced significantly showed a minimum with increasing the dosage. The amidation ratio of SMANS has a great impact on reducing viscosity of PS latex. Cross model was employed to quantitatively describe the rheological behavior of PS latex.In order to study rheological behavior of CWS, effects of coal properties, dispersants and continuous phase on rheology of CWS were studied. Properties of Shenfu coal were invested by proximate analysis, ultimate analysis and FT-IR method. Rheological properties of CWS were studied by using rheometer. The apparent viscosity of CWS increased sharply when concentration was above 55%. In order to improve flow ability of CWS, amphiphilic copolymer SMANS was added as dispersant. Apparent viscosity and yield stress of CWS reduced significantly with the addition of SMANS. Both amount and amidation ratio of SMANS has a great impact on rheology of CWS. Viscosity of CWS reduced showed a minimum with increasing the dosage. Effects of the amidation ratio of SMANS were also investigated by addition of three kinds of SMANS with different amidation. In order to study effects of continuous phase on rheology of coal slurries, three kinds of alcohol were used to prepare coal slurries instead of water. Coal alcohol slurries usually showed higher viscosity and yield stress compared to CWS due to the swelling of coal.