Kinetic Modelling of the Synthesis of Polycarboxylate Ethers Via Partial Esterification of Acrylic Copolymers

In this work, the synthesis of polycarboxylate ethers (PCE) via partial esterifica-tion of acrylic copolymers has been experimentally carried out with the aim of obtaining results useful to the development of a reliable kinetic model. Method: Experimental tests were conducted starting from monomethyl ether polyethylene glycol (MPEG) as side chain, and two acrylic backbones of different constitution. The reactions were carried out in a 350 mL batch reactor made of glass. Thirteen PCE polymers have been produced varying the target esterification degree (15–45%), reaction temperature (150–180°C) and time (60–460 min). Results: The results of degree of MPEG conversion, obtained through gel permeation chromatog-raphy, have been fitted with different kinetic models through a devoted software and procedure. The model resulting in a very satisfying fitting was based on a kinetic equation of pseudo 1st-order with respect to the MPEG concentration, and pure 1st-order with respect to the concentration of carboxylic groups. Once the kinetic parameters have been determined, the model has been validated against ex-perimental data obtained under different and additional operating conditions in terms of esterification degree and operating temperature. Conclusion: The good fitting with the experimental data of MPEG conversion under the new operat-ing conditions witnesses the soundness of the proposed approach.