Publications [#62118] of Kam W. Leong

Papers Published

1. Li, Xu and Li, Jun and Leong, Kam W., Preparation and characterization of inclusion complexes of biodegradable amphiphilic poly(ethylene oxide)-poly[(R)-3-hydroxybutyrate]-poly(ethylene oxide) triblock copolymers with cyclodextrins, Macromolecules, vol. 36 no. 4 (2003), pp. 1209 - 1214 [ma0213347]
   (last updated on 2007/04/13)

   Abstract:
   Inclusion complexes (ICs) of biodegradable amphiphilic poly(ethylene oxide)-poly[(R)-3-hydroxybutyrate]-poly(ethylene oxide) triblock copolymers with α-cyclodextrin (α-CD) or γ-cyclodextrin (γ-CD) were prepared from aqueous medium. The ICs were characterized by XRD, DSC, ¹³C CP/MAS NMR, ¹H NMR, FTIR, and TGA. The results of XRD and ¹³C CP/MAS NMR indicated that the ICs formed channel structure, and the α-CD or γ-CD molecules in the ICs adopted a more symmetric conformation compared with their uncomplexed states. As to the triblock copolymers, while the poly(ethylene oxide) blocks were included in the channel structure, the poly[(R)-3-hydroxybutyrate] block was partially threaded by α-CD or γ-CD, which was confirmed by the results of XRD, DSC, ¹H NMR, and FTIR. The formation of ICs led to an increase in the thermal stability of both cyclodextrins and the triblock copolymers.

   Keywords:
   Biodegradation;Inclusions;Copolymers;Solutions;Structure (composition);Integrated circuits;X ray diffraction analysis;Nuclear magnetic resonance;Fourier transform infrared spectroscopy;