Synthesis of acid degradable oxidation responsive poly(β-thioether ester)s from castor oil.

Graphical abstract Highlights • Synthetic protocols are developed to prepare diesters and hydroxyesters from heptanal. • Amphiphilic diblock copolymers were obtained by lipase polycondensation using mPEG. • Micelles of increasing size with increasing hydrophobic block content were obtained. Abstract Branched polyesters with acid degradable and oxidation responsive β-thiopropionate groups have been obtained by lipase catalyzed polycondensation of diester and hydroxyester monomers from heptanal, a castor oil derivative. Their polymerization behavior has been investigated and poly(ethylene glycol)- b -poly(β-thioether ester) amphiphilic block copolymers have been obtained. SEC, NMR and FTIR have been employed to confirm the structure of the polymers and copolymers and DSC and TGA have been used to characterize their thermal properties. The block copolymers containing aliphatic pendant moieties self-assemble into micelles in aqueous solution, showing potential application as dual responsive systems in drug delivery. [ABSTRACT FROM AUTHOR]