Polymerization Mechanism and Kinetics of Preparation of Methacrylic Acid-Ethyl Acrylate Copolymer Emulsion Reverse Demulsifier

Abstract

It was shown that methacrylic acid-ethyl acrylate copolymer (P(EA-MAA)) emulsion has a good reverse demulsification performance for treatment of water produced in oilfields. Its polymerization mechanism, kinetics and demulsification mechanism are important for its application and scale-up production. Therefore, they were studied in the research described in this paper. It was found that the demulsification mechanism of P(EA-MAA) was related to the ion compositions of the produced water and the conformation change of P(EA-MAA) when it was dissolved in the produced water. The distributions of monomer and surfactant before the polymerization were investigated and we found that there were both homogeneous nucleation and micellar nucleation during the first stage of emulsion polymerization. The relationships among the polymerization rate (Rp), monomer concentration ([M]), initiator concentration ([I]) and surfactant concentration ([S]) were studied. The emulsion copolymerization kinetic equation was Rp∝[M]0.64 [I]0.68 [S]0.41, which is related with the nucleation mechanism of the polymerization mechanism. In addition, the activation energy was 34.50 kJ/mol.