Kinetics of PTSA-Catalysed Polycondensation of Citric Acid with 1,3-Propanediol

Recent years have seen the intensive development of novel therapies based on stem cells and advanced materials. Among the latter, polymers, especially polyesters, occupy a special place and are being investigated for use as substrates for cell differentiation and culture. Increasing application requirements are driving demand for such materials. This study aims to obtain a new material with potential biomedical applications, poly(1,3-propanediol citrate). A spectral analysis of the obtained product was carried out. The reaction kinetics of the polycondensation of citric acid and 1,3-propanediol in the presence of a catalyst, p-toluenesulphonic acid (PTSA), are described. The basis for determining the polycondensation kinetics was the assumption of non-equivalence of the carboxyl groups in citric acid. Elementary reaction rate constants and activation energy values were determined. Based on the data obtained, the course of the gelation points of the reaction mixture was estimated in its dependence on the temperature and reaction time. Kinetic research will facilitate the scale-up of the process.