Poly(butylene succinate)-based composites containing beta-cyclodextrin/D-limonene inclusion complex

Structural, morphological and thermal properties of films based on poly(butylene succinate) (PBS) and inclusion complex (IC) of beta-cyclodextrins (beta-CD) and D-limonene were studied, in order to prepare novel bio-active food packaging materials. Formation of the inclusion complex was proved by infrared spectroscopy, nuclear magnetic resonance, and X-ray diffraction. The IC contains 7 wt% of D-limonene, as quantified by precipitation, as well as by C-13 NMR and by thermogravimetry. Inclusion within beta-CD cavity stabilizes D-limonene against evaporation, which allows melt compounding with PBS. Infrared spectroscopy of compression molded composite films, evidenced both the D-limonene encapsulation inside beta-CD cages, and the occurrence of interactions between hydroxyl groups of beta-CD-lim complex and the carbonyl groups of PBS units. Optical micrographs showed a phase separated morphology, with homogeneous distribution of the IC within the PBS matrix, probably due to interactions between the polar groups of the composite components. DSC analysis highlighted the anti-nucleating action of beta-CD-lim complex towards PBS, evidenced by a significant delay in crystallization kinetics of PBS. (C) 2016 Elsevier Ltd. All rights reserved.