Abstract
| Language | English |
|---|---|
| Pages | 7388-7395 |
| Number of pages | 8 |
| Journal | Macromolecules |
| Volume | 42 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - 13 Oct 2009 |
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Keywords
- multiblock copolymers
- lactic acid
- ethylene glycol
- synthesis
- characterization
- nanoparticle preparation
- periodic side-chain carboxyl groups
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Multiblock copolymers of lactic acid and ethylene glycol containing periodic side-chain carboxyl groups : synthesis, characterization, and nanoparticle preparation. / Ankola, D. D.; Kumar, M.N.V. Ravi; Chiellini, F.; Solaro, R.
In: Macromolecules, Vol. 42, No. 19, 13.10.2009, p. 7388-7395.Research output: Contribution to journal › Article
TY - JOUR
T1 - Multiblock copolymers of lactic acid and ethylene glycol containing periodic side-chain carboxyl groups
T2 - Macromolecules
AU - Ankola, D. D.
AU - Kumar, M.N.V. Ravi
AU - Chiellini, F.
AU - Solaro, R.
PY - 2009/10/13
Y1 - 2009/10/13
N2 - 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.
AB - 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.
KW - multiblock copolymers
KW - lactic acid
KW - ethylene glycol
KW - synthesis
KW - characterization
KW - nanoparticle preparation
KW - periodic side-chain carboxyl groups
U2 - 10.1021/ma9012253
DO - 10.1021/ma9012253
M3 - Article
VL - 42
SP - 7388
EP - 7395
JO - Macromolecules
JF - Macromolecules
SN - 0024-9297
IS - 19
ER -