Novel chemical recycling of poly(L-lactic acid) using montmorillonite K10

In order to establish the sustainable chemical recycling process of poly(L-lactic acid), poly(L-lactic acid) with a molecular weight of 100,000 was transformed into the corresponding lactate oligomers having a molecular weight of few hundreds by using environmentally benign solid acids, such as Montmorillonite K10. Oligomerization reaction was independent of the polymer concentration in toluene. The oligomer could be repolymerized by the conventional chemical catalysts forming a high molecular weight poly(L-lactic acid). It was confirmed that the chemical recycling process was a stereoretention process.