Hexaarmed star-shaped hydroxyl-terminated
poly(e-caprolactone) (PCL) was successfully synthesized via
the ring-opening polymerization of e-caprolactone (CL) with
hexakis[p-(hydroxymethyl)phenoxy]cyclotriphosphazene initiator
and stannous octoate catalyst in bulk. The star-shaped
PCL with hydroxy end groups could be used as amacroinitiator
for block copolymerization with L-lactide (L-LA). The starshaped
triblock copolymer was synthesized by above-mentioned
hydroxyl-terminated star-shaped diblock PCL-b-PLLA,
D,L-lactide (D,L-LA), and glycolide (GA). IR, 1HNMR, andGPC
analysis showed that the star-shaped block copolymers were
successfully synthesized and the molecular weights and the
unit composition of the star-shaped block copolymers were
controlled by the molar ratios ofmonomer to initiator. The triblock
copolymer presented a three-phase structure, namely,
PCL crystalline, PLLA crystalline, and D,L-PLAGAamorphous
domains, which made the triblock copolymer different from
the diblock copolymer and star-shaped PCL in crystallizability
and thermal behaviors. Then, the in vitro degradation behaviors
of the copolymers were investigated.