Bulk polycondensation of lactic acid by Maghnite-H⁺ a non-toxic catalyst

In this study, we report a novel approach to preparing poly (D, L-lactic acid) (PLA) as a biodegradable polymer. PLA was prepared by direct polycondensation of D, L-lactic acid using Maghnite-H⁺, a non-toxic proton exchanged Montmorillonite clay, as catalyst. We investigated in detail, the reaction conditions for the simple direct polycondensation of D,L-lactic acid, including the reaction times, temperatures, and catalyst amount. The molecular weight of synthesized PLA is dependent on both the reaction temperature, amount of catalyst and time. Kinetics indicated that the polycondensation of lactic acid behaves as second-order reaction mechanism. The method for PLA synthesis established here will facilitate production of PLA of various molecular weights, which may have a potential utility as biomaterials.