The Effect of Various Catalytic Systems on Solid-State Polymerization of Poly-(L-lactic acid)

There are several methods for synthesizing polylactic acid. Solid-state polymerization is one of the most promising methods due to the great feasibility and beneficial properties of the final polymer. In terms of this study, the purpose was to evaluate the effect of various catalyst systems (based on tin dichloride, tin dioxide, tin octoate, citric acid, sulphuric acid, toluenesulfonic acid and methane sulfonic acid) and focus on the molecular weight, structure and thermal properties of the final products. The molecular weight was shown to be controlled by different catalytic systems and M-w > 100,000 g/mol was achieved after 24 h of synthesis, which is more than in the conventional melt polycondensation process. Thermal stability was found to be negatively affected by the catalytic system, although relatively positive results can still be achieved.