AbstractPolycondensation polymers are normally produced through bulk and solution polymerization processes, which are characterized by significant mass and heat transfer constraints and difficult polymer purification (when prepared in solution). Therefore, it is desirable to develop industrial processes that can circumvent some of these limitations. Recently, a suspension polycondensation process has been developed, rendering the industrial process simpler and enabling the manufacture of polycondensation polymer microparticles. For this reason, the present work builds a phenomenological model to describe the analyzed suspension polycondensation reactions and estimate the model parameters required to simulate poly(butylene succinate) suspension polycondensations. It is shown that both the suspending medium and the reaction conditions can affect the mass transfer resistance for removal of water and that mass transfer rate coefficients are controlled mainly by reaction temperature and solubility of water in the suspending medium, leading to higher mass transfer rates when polymerizations are carried out in soybean oil (when compared to paraffin) at higher temperatures.