Picture of a black hole

Strathclyde Open Access research that creates ripples...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of research papers by University of Strathclyde researchers, including by Strathclyde physicists involved in observing gravitational waves and black hole mergers as part of the Laser Interferometer Gravitational-Wave Observatory (LIGO) - but also other internationally significant research from the Department of Physics. Discover why Strathclyde's physics research is making ripples...

Strathprints also exposes world leading research from the Faculties of Science, Engineering, Humanities & Social Sciences, and from the Strathclyde Business School.

Discover more...

Multiblock copolymers of lactic acid and ethylene glycol containing periodic side-chain carboxyl groups : synthesis, characterization, and nanoparticle preparation

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 0024-9297

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

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.