Synthesis, performance and mechanism of a hyperbranched polymer with diethyl diphenyl-p-phenylenediamine as centronucleus

A hyperbranched polymer (PDPD) was synthesized using diethyl diphenyl-p-phenylenediamine as centronucleus. Its chemical structure was characterized by H-1 NMR and FT-IR, and thermal stability was evaluated by ther-mogravimetric analysis. The effect of concentration, temperature, settling time and salinity on the demulsifi-cation performance was systematically studied in oily wastewater. The transmittance of separated water (TSW) and oil removal ratio (ORR) could reach 85.7% and 99.6%, respectively, after demulsifying with 80 mg/L of PDPD for 4 h at 25 degrees C. Moreover, PDPD also had high salt tolerance. In addition, the dynamic interfacial tension (IFT), zeta potential and microscopic observation were utilized to explore a possible demulsification mechanism. This work not only provides a new hyperbranched demulsifier for the demulsification of oily wastewater, but also brings some references for the study of demulsification mechanism.