Influence of low-energy electron beam treatment on crystallization of PLLA and PLLA/PDLA blends

The use of heterogeneous nucleating agents enhances the stereocomplex (SC) crystallization in polylactide (PLA) blends, but affects their biocompatibility and applicability, e.g. in medical applications. Low-energy electron beam (LEEB) treatment was used to prepare self-nucleating agents from poly (L-lactic acid) (PLLA) and poly (D-lactic acid) (PDLA), enabling SC crystallization without heterogeneous nucleating agents. Differential scanning calorimetry, including both non-isothermal and isothermal measurements, was used to study the total crystallinity and the crystallization time of PLLA/PDLA blends containing LEEB modified PLLA and PDLA. The results demonstrate that LEEB treatment of both blend components increased the SC crystallinity to about 40 % and reduces the crystallization time by about 40 % at a temperature of 170 °C. At higher doses, excessive chain scission disrupts chain regularity and reduces homo-crystal formation. LEEB-induced self-nucleation strategy enables enhanced SC content and reduced crystallization time without additives and offers a potential approach for developing high-performance PLA-based materials.