Abstract
Dispersion properties of the water soluble phenol-formaldehyde resin are studied by measuring of hydrodynamic diameter, Zeta potential of the resin molecule aggregate and the critical coagulating concentration of the resin solution. The results shows that a 50 mg/L resin solution prepared with distilled water is transparent, in which the hydrodynamic diameter and the Zeta potential of the resin molecule aggregate is about 9 nm and −38.08 mV, respectively. With addition of electrolytes, the Zeta potential of the resin molecule aggregate is decreased, and the solution turns turbid. The ratio of critical coagulating concentration (CCC) of NaCl to MgCl2, AlCl3, Na2SO4 for the resin solution is 1 : 0.026 : 0.00033 : 0.49. pH can also influence the resin dispersion significantly. When the pH > 7, the resin aggregate is negatively charged with a high Zeta potential, and the solution is stable. The isoelectric point of the aggregate is pH around 3.2. When the pH < 3.2, the resin aggregate is positively charged with Zeta potential of 3 ∼ 5 mV, the system becomes a turbid suspension.