Synthesis of 4-arm star poly(L-Lactide) oligomers using an in situ-generated calcium-based initiator
George, Karina A., Schue, Francois, Chirila, Traian, & Wentrup-Byrne, Edeline (2009) Synthesis of 4-arm star poly(L-Lactide) oligomers using an in situ-generated calcium-based initiator. Journal of Polymer Science Part A: Polymer Chemistry, 47(18), pp. 4736-4748.
Using an in situ-generated calcium-based initiating species derived from pentaerythritol, the bulk synthesis of well-defined 4-arm star poly(L-lactide) oligomers has been studied in detail. The substitution of the traditional initiator, stannous octoate with calcium hydride allowed the synthesis of oligomers that had both low PDIs and a comparable number of polymeric arms (3.7 – 3.9) to oligomers of similar molecular weight. Investigations into the degree of control observed during the course of the polymerization found that the insolubility of pentaerythritol in molten L-lactide resulted in an uncontrolled polymerization only when the feed mole ratio of L-lactide to pentaerythritol was 13. At feed ratios of 40 and greater, a pseudo-living polymerization was observed. As part of this study, in situ FT-Raman spectroscopy was demonstrated to be a suitable method to monitor the kinetics of the ring-opening polymerization (ROP) of lactide. The advantages of using this technique rather than FT-IR-ATR and 1H NMR for monitoring L-lactide consumption during polymerization are discussed.
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|Item Type:||Journal Article|
|Keywords:||poly(L-lactide), star polymers, Raman spectroscopy, kinetics (polym.) , heterogeneous polymerization|
|Subjects:||Australian and New Zealand Standard Research Classification > CHEMICAL SCIENCE (030000) > MACROMOLECULAR AND MATERIALS CHEMISTRY (030300) > Polymerisation Mechanisms (030305)|
Australian and New Zealand Standard Research Classification > CHEMICAL SCIENCE (030000) > MACROMOLECULAR AND MATERIALS CHEMISTRY (030300) > Synthesis of Materials (030306)
|Divisions:||Past > Schools > Chemistry|
Past > QUT Faculties & Divisions > Faculty of Science and Technology
Current > Institutes > Institute of Health and Biomedical Innovation
|Copyright Owner:||Copyright 2009 Wiley-Blackwell|
|Deposited On:||24 May 2010 07:21|
|Last Modified:||01 Mar 2012 00:04|
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