Separation of Monoester and Diester in the Esterification Product of Polyethylene Glycol and Acrylic Acid by the Weibull Method

• DOI: 10.1007/s11743-011-1267-2
• Publication Date: 2011-04-05T17:29:11Z
• Authors: Jia‐Heng Lei; Hui Li; An‐Fu Zhang; Xiao‐Di Du; Qian Lu
• Keywords: 0205 materials engineering; 02 engineering and technology; 6. Clean water

AbstractIn the extraction system of ethyl acetate and NaCl aqueous solution, partition coefficients of polyethylene glycol mono‐acrylate (PEGmA) and polyethylene glycol di‐acrylate (PEGdA) varied with temperature and concentration of NaCl solution were studied. The best separation condition of PEGmA and PEGdA was determined on that basis. Results of the testing showed that partition coefficients of PEGmA and PEGdA sharply increased with rising concentration of NaCl solution and temperature. Since the incremental degrees of PEGmA and PEGdA were different from each other, the ratio of partition coefficient (KPEGdA/KPEGmA) reached a maximum under the conditions of 20 °C and 5 mol L−1 NaCl. The best separating condition was as follows: PEGdA was extracted out with ethyl acetate by adding 5 mol L−1 NaCl at 20 °C. After three repetitions, the recovery rate of PEGdA reached 99.8%. The water phase was heated to 50 °C and PEGmA was extracted out with ethyl acetate. The recovery rate of PEGmA amounted to 68.8% by three repetitions. After washing and drying, the purity of PEGmA and PEGdA was 99.7 and 98.7% respectively.