Table 1.
Synthesis of MPEG-b-(PCL-co-PLA) (PCxLyA) copolymers.
| Polymer | Molar Ratio (%) (CL/LA) a | Yield (%) b | Mn a | MW/Mn c |
|---|---|---|---|---|
| PC7L3A | 70/30 | 90 | 530,000 | 1.7 |
| PC6L4A | 61/39 | 89 | 516,000 | 1.6 |
| PC5L5A | 51/49 | 92 | 498,000 | 1.4 |
| PC4L6A | 38/62 | 93 | 521,000 | 1.7 |
| PC3L7A | 28/73 | 91 | 512,000 | 1.5 |
Initiator is methoxy poly(ethylene glycol) (MPEG); Condition: [Sn(Oct)2]/[Initiator] = 1.2; ([ε-CL] + [LA])/[toluene] = 2.8 M, 130 °C, 24 h; a Determined by proton nuclear magnetic resonance (1H-NMR) spectroscopy; b n-Hexane/diethyl ether (4/1) insoluble part; c Measured by gel permeation chromatography (GPC) (Based on polystyrene standards). CL: caprolactone; LA: lactic acid; Mn: the number average molecular weight; MW: the weight average molecular weight.