Nonionic surfactants from poly(ethylene terephthalate) waste: II. Effect of temperature, salinity, pH-value, and solvents on the demulsification efficiency

The effect of temperature, NaCl concentration (salinity), pH-value, and solvents on the demulsification efficiency of the demulsifiers synthesized from poly(ethylene terephthalate) waste [polyoxyethylenated glycolized product of PET (POGP)] in breaking synthetic water-in-benzene emulsions stabilized by petroleum asphaltenes have been investigated. The demulsification efficiency of the studied polymeric surfactants was found to increase as the temperature was raised and the salinity of the aqueous phase decreased. Neutral pH-value of the aqueous phase of the emulsion was found to be the optimum value causing maximum demulsification efficiency. Water and 1, 2 propylene glycol were found to be the best solvents for the prepared demulsifiers offering maximum demulsification efficacy.