Ankola, D. D. and Kumar, M.N.V. Ravi and Chiellini, F. and Solaro, R. (2009) Multiblock copolymers of lactic acid and ethylene glycol containing periodic side-chain carboxyl groups : synthesis, characterization, and nanoparticle preparation. Macromolecules, 42 (19). pp. 7388-7395. ISSN 0024-9297Full text not available in this repository. (Request a copy from the Strathclyde author)
Multiblock copolymers containing periodically spaced side-chain carboxyl groups were obtained by a two-step synthesis involving the preparation of ABA triblock prepolymers of lactic acid (A block) and ethylene glycol (B block) followed by chain extension to (ABA)n multiblock copolymers by reaction with pyromellitic dianhydride (PMDA). A series of polymer grades were synthesized by varying PEG and PLA chain length. NMR analysis demonstrated the incorporation of PMDA in polymer chain and revealed the possibility of PMDA units to exist in two isomers, cisoid and transoid forms. Chain extension resulted in the incorporation of free carboxylic groups in polymer backbone and in a 6-fold increase of molecular weight. Thermal analysis indicated that the extended polymers are more stable and have a Tg of 30−50 °C higher than their prepolymers. The polymers were found to be fast degrading in water following coupled first-order kinetics. Further, the carboxylated polymers can be processed into nanoparticulates by either nanoprecipitation or emulsion−diffusion methods resulting in 50−200 nm sized particles.
|Keywords:||multiblock copolymers, lactic acid, ethylene glycol, synthesis, characterization, nanoparticle preparation, periodic side-chain carboxyl groups, Pharmacy and materia medica, Materials Chemistry, Organic Chemistry, Polymers and Plastics, Inorganic Chemistry|
|Subjects:||Medicine > Pharmacy and materia medica|
|Department:||Faculty of Science > Strathclyde Institute of Pharmacy and Biomedical Sciences|
|Depositing user:||Strathprints Administrator|
|Date Deposited:||21 Jun 2010 13:46|
|Last modified:||27 Apr 2016 15:17|