M. Acemoglu et al., POLY(ETHYLENE CARBONATE)S, PART I - SYNTHESES AND STRUCTURAL EFFECTS ON BIODEGRADATION, Journal of controlled release, 49(2-3), 1997, pp. 263-276
Poly(ethylene carbonate)s (PECs) of different molecular weights (Mws)
were synthesized by copolymerization of CO2 and ethylene oxide using d
ifferent catalyst systems. Et2Zn/ethylene glycol was found to be excep
tionally effective as a catalyst for this copolymerization. PECs synth
esized using this catalyst were characterized by very high ethylene ca
rbonate content, low polydispersity and high glass transition temperat
ures. The in vivo biodegradability of PECs was found to be affected by
the content of ether functions in the polymer chain, by the Mw of the
products and by the catalyst used to prepare them. Surprisingly, the
biodegradation of PECs having Mws<100 000 is strongly suppressed, whil
st PECs with Mw>130 000 show almost identical in vivo biodegradation b
y surface erosion. (C) 1997 Elsevier Science B.V.