Guanghua Zhang

Impact of the length of PEO side chain on the properties of polycarboxylate copolymers in coal-water suspensions

To investigate the effect of side-chain structure of comb-like polycarboxylates (PCs) on their dispersion and stability properties for coal-water suspensions (CWSs), comb-like PCs with polyethyleneoxide (PEO) of different lengths were synthesized using allyl polyoxyethylene ether (APEG, Mw = 700,1000,1200,2400). PCs were characterized and used as the dispersants for the low rank Binchang CWSs. The apparent viscosity, rheology, stability, adsorption (Γ∞), and zeta potential value (ζ) of coal-water suspensions were systematically explored. The results showed that the CWSs displayed the dispersing effect, adsorption amount on the coal of PCs, and zeta potential enhanced in the same order of PC2400 < PC1200 < PC700 < PC1000. The findings reported in this work reveal that the PCs adsorbed on the surface of coal particles formed an electric double layer. The stability of the electric double layer improves with PC adsorption amount soaring and be simultaneously affected by PEO side chain of varying lengths. The PC with moderate length of PEO side chain is found to have the best dispersibility for coal-water suspensions.