Thermal and Thermo-Mechanical Properties of Poly(L-lactic Acid) Biocomposites Containing β-Cyclodextrin/d-Limonene Inclusion Complex
Monika Dobrzyńska‐Mizera, Monika Knitter, Salvatore Mallardo, Maria Cristina Del Barone, Gabriella Santagata, Maria Laura Di Lorenzo
Abstract
Bio-based composites made of poly(L-lactic acid) (PLLA) and β-cyclodextrin/d-limonene inclusion complex (CD-Lim) were prepared by melt extrusion. Encapsulation of volatile d-limonene molecules within β-cyclodextrin cages was proven to be a successful strategy to prevent evaporation during high-temperature processing. However, small amounts of limonene were released upon processing, resulting in the plasticization of the polymeric matrix. Morphological analysis revealed good dispersion of the filler, which acted as a nucleating agent, favoring the growth of PLLA crystals. The composites' lowered glass transition temperature upon the addition of CD-Lim was also proved by thermomechanical analysis (DMA). Moreover, DMA revealed constant stiffness of modified materials at room temperature, which is crucial in PLLA-based formulations.