Synthesis of 3H and fluorescence-labelled poly (DL-Lactic acid)

✍ Scribed by S. Ponsart; J. Coudane; J.-L. Morgat; M. Vert

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: French
• Weight: 118 KB
• Volume: 44
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.495

✦ Synopsis

The novel polymer modification method based on the activation of an aliphatic polyester chain by using lithium diisopropylamide at low temperature to form a polycarbanion bearing nucleophilic sites in a position a to the carbonyl groups was applied to rac-poly (lactic acid), PLA 50 , to label this polymer with radioactive tritium atoms or with a fluorescent dye. Despite simultaneous partial chain degradation, radioactive PLA 50 and fluorescent PLA 50 with M n ¼ 14 000 g mol À1 , M w =M n ¼ 1:9 and M n ¼ 32 000 g mol À1 , M w =M n ¼ 2:4, respectively, were obtained. The specific activity of the final compound was 3.7 mCi g À1 that squared with 0.3% substitution reaction. The fluorescent polymer was substituted with 0.25% ratio. This work shows that the LDA activation method appears to have considerable potential.