Preparation and Characterization of Cross-linked Hollow Poly(lactic acid) Microspheres
writer：B.B. JIANG, C.Y.GAO, J.C. SHEN
keywords：Emulsion polymerization,Polyl(lactic acid),Hollow microspheres
source：期刊
specific source：Chemical Journal of Chinese Universities
Issue time：2005年
Poly(lactic acid) macromonomer with a double bond at its end was
synthesized by ring open polymerization of lactide catalyzed by stannous
chloride in the presence of allyloxylethanol(AOE) as a co-initiator.
Its molecular weight was decreased along with the adding amount of AOE.
Initiated by an oxidation-reduction system, e.g. K2S2O8 and Na2SO3, the
poly(latic acid) macromonomers were copolymerized with divinylbenzene
and methacrylic acid in a water-in-oil-in-water emulsion manner to
produce hollow microspheres with a size of hundreds nanometers. Their
hollow structure was confirmed by transmission electron microscopy.
Infrared spectroscopy measurement shows that the remainings of the
microspheres after tetrahydrofuran extraction, constituting roughly 20
of the sphere''s mass, contained all the initial monomer components. This
provides a new pathway for fabricating biodegradable hollow
microspheres with rather smaller size, which may find diverse
applications in the fields of drug delivery, tissue engineering and
nanotechnology.