Inclusion Compounds Formation of Poly(azomethine ether)s and β‐Cyclodextrin

Structure and properties of poly(lactic acid)/poly(lactic acid)-α-cyclodextrin inclusion compound composites

Poly(lactic acid) (PLA) was synthesized using a green catalyst, nano-zinc oxide (ZnO). The optimum synthesis conditions of PLA were as follows: a stoichiometric amount of 0.5 wt% of nano-ZnO, polymerization time of 14 h, and polymerization temperature of 170°C. Gel permeation chromatography results showed that the weight-average molecular weight (Mw) of PLA was 13,072 g/mol with a polydispersity index (PDI) of 1.7. Furthermore, PLA-α-cyclodextrin inclusion compounds (PLA-CD-ICs) were prepared by ultrasonic co-precipitation techniques. X-ray diffraction analysis and Fourier transform infrared spectroscopy demonstrated the change in lattice of α-CD from a cage configuration to a tunnel structure and the existence of some physical interactions between α-CD and PLA in the PLA-CD-ICs. To enhance the crystallization properties of PLA, PLA/PLA-CD-IC composites were blended with different contents of PLA-CD-ICs as nucleating agents. The crystallization behavior and comprehensive performance were investigated by differential scanning calorimetry, polarized optical microscopy, tensile testing, dynamic mechanical analysis, and scanning electron microscopy. Compared to PLA, the crystallinities of PLA/PLA-CD-IC composites were increased by 24.0%, 26.3%, 27.3%, and 31.8%. The results of all the analyses proved that PLA-CD-ICs were useful as green organic nucleators and improved the comprehensive performance of PLA materials.

An easy approach for constructing vesicles by using aromatic molecules with β-cyclodextrin

Vesicles were formed in aqueous solution using β-cyclodextrin (β-CD) complexes with a series of ultra-small aromatic molecules. The vesicles are easy to prepare without a complicated synthesis procedure and their structure was identified and characterized using various techniques, including transmission electron microscopy, atomic force microscopy and dynamic laser light scattering. Using the β-CD/l-phenylalanine system as a representative example, the structural factors that caused the self-assembly were revealed using proton nuclear magnetic resonance, Fourier transform infrared spectroscopy and X-ray diffraction. In addition, the vesicular architecture could be endowed with a diverse range of stimuli-responses, as a consequence of the selective addition of various guest molecules. It is anticipated that this novel assembly strategy could be further extended, and that it presents new opportunities for the development of nanocarriers and soft materials.