An outlook on recent progress in poly(lactic acid): polymerization, modeling, and optimization

Poly(lactic acid) has emerged as a capable biodegradable polymer which has been proved to be an appropriate alternative for polyolefin. Monomer lactic acid being fermented by renewable sources makes it more reliable. Polycondensation of lactic acid and ring-opening polymerization (ROP) of lactide are the two extensively used polymer synthesis methods since 1900s that have been discussed in this study. Molecular weight up to 104–105 Da and conversion by 97–98% have been obtained with varying operating conditions with respect to their stereoisomerism for synthesizing lactic acid and its polymerization. As the experimental procedure is time consuming and challenging, mathematical modeling for reaction mechanism of polymerization by considering previous experimental knowledge is an uncomplicated and significant approach. Parameters such as initial concentration of monomer, catalyst, and co-catalyst and temperature are significant for simulating the kinetic model. Experimental design plays an important role in planning and designing experiments and analyzing the result to provide an optimal solution for the kinetics of the system. In this review, new technologies and methods used by researchers to synthesize PLA to obtain better properties and modeling and simulation of the kinetic mechanism by PC and ROP and their further gradation to develop more precise solution through optimization studies as an outcome of experimental studies will be discussed.