In this article, our main goal is to combine hyperbranched polymer with
b-cyclodextrin (b-CD) to establish a novel functional polymer species with core-shell
structure and supramolecular system for further application in inclusion technologies
and the complex drugs delivery system. Therefore, two b-CD polymer brushes based
on hyperbranched polycarbosilane (HBP) as a hydrophobic core and poly(N,N-dimethylaminoethyl
methacrylate) (PDMA) carrying b-CD units as a hydrophilic shell
were synthesized. Hyperbranched polycarbosilane macroinitiator carrying Cl
groups (HBP-Cl) was also prepared by using 1,1,3,3-tetrmethyldisiloxane, allyl alcohol,
and chloroacetyl chloride as reagents. The molecular structures of HBP-Cl macroinitiator
and b-CD polymer brushes were characterized by Fourier transform infrared
spectroscopy (FTIR), 1H nuclear magnetic resonance (1H NMR), 13C nuclear magnetic
resonance (13C NMR) spectroscopies, size exclusion chromatography/multi-angle
laser light scattering (SEC/MALLS) and laser particle size analyzer. The results indicate
that the grafted chain length of two b-CD polymer brushes can be controlled by
changing the feed ratio. Differential scanning calorimetry (DSC) results show that
two b-CD polymer brushes have two glass transition temperatures (Tgs) from a
hydrophobic core part and a hydrophilic shell part, respectively, and the Tg from
PDMA is higher than that of HBP-g-PDMA. Thermalgravimetric analyzer (TGA)
analysis indicates that the thermostability of two b-CD polymer brushes is higher
than that of HBP, but is lower than that of HBP-g-PDMA. Using phenolphthalein
(PP) as a guest molecule, molecular inclusion behaviors for two b-CD polymer
brushes were studied. It reveals that two b-CD polymer brushes possess molecular
inclusion capability in PP buffer solution with a fixed concentration.
