A microreactor platform with easily assembled reaction tubes is developed to study the kinetics of acrylic acid polymerization in aqueous solutions. In this platform, two micromixers are used to start and terminate the polymerization reaction, and several coiled reaction tubes embedded in water baths control the residence time. Operated at a total flow rate greater than 40 mL/min, the reaction is independent of the monomer and initiator mixing. Experimental data showed that the orders of acrylic acid and potassium persulfate were 1.5 and 0.5, respectively, with an activation energy of 67.4 kJ/mol, which is in accord with the classical kinetic mode reported in the literature. The molecular weight of polyacrylic acid (1.03 x 10(5)-1.76 x 10(5)) also indicated that the microreactor platform works well with macromolecules. Therefore, this technique will expand the viable methods applicable for kinetic studies. (C) 2015 Elsevier B.V. All rights reserved.