Key Words:RAC-LACTIDE; BIODEGRADABLE COPOLYMERS; ALIPHATIC POLYESTERS; ZIRCONIUM COMPOUNDS; POLYMERIZATION; PLGA; SEQUENCE; BEHAVIOR; ORGANOCATALYSTS; POLYLACTONES
Abstract:The preparation of poly(lactic-co-glycolic acid) (PLGA) copolymers with controllable random microstructures remains as a challenge due to the much higher reactivity of glycolide (GA) compared to lactide (LA). In this contribution, we present the one-pot ring-opening copolymerization (ROCOP) of LA with GA to produce random PLGA copolymers with tunable monomer sequence lengths using an organophosphazene base/urea binary catalyst. Ultrafast copolymerizations with high monomer conversions (>95%) were achieved at ambient temperature within a few seconds. A series of PLGA copolymers with molar masses ranging from 4.6 to 13.0 kDa were obtained by changing monomer feeding ratios. The microstructures of the obtained PLGA copolymers can be tuned by changing the feeding molar ratio of LA/GA, and were carefully characterized using C-13 NMR spectroscopy. The thermal properties of PLGA copolymers were also explored, and they exhibited composition dependent behaviors.
Volume:13
Issue:13
Translation or Not:no