Jc. Ha et al., Poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (pluronic)/poly(epsilon-caprolactone) (PCL) amphiphilic block copolymeric nanospheres- I. Preparation and characterization, J CONTR REL, 62(3), 1999, pp. 381-392
Amphiphilic block copolymers based on PEO-PPO-PEO block copolymer (Pluronic
) and poly(epsilon-caprolactone) were synthesized by bulk polymerization. T
he structural analysis of Pluronic/PCL block copolymer was carried out usin
g FT-IR, H-1 NMR, GPC, WAXD, DSC and TGA measurements. To prepare copolymer
ic nanospheres with a micellar structure, Pluronic/PCL amphiphilic block co
polymers were dialyzed against water. The size and size distribution of Plu
ronic/PCL block copolymeric nanospheres were examined by dynamic light scat
tering measurement. They showed an average diameter of 116 to 196 nm depend
ing on the type of copolymer. All the nanosphere samples exhibited a narrow
size distribution. The critical micelle concentrations of Pluronic/PCL amp
hiphilic block copolymers determined by fluorescence spectroscopy were lowe
r than that of common low molecular weight surfactants. We confirmed the fo
rmation of stable copolymeric nanospheres through the solution behavior of
amphiphilic block copolymer in selective solvents. (C) 1999 Elsevier Scienc
e B.V. All rights reserved.