Synthesis and characterization of self-catalyzed poly(ortho-esters) based on decanediol and decanediol-lactate.

The synthesis of poly(ortho-esters) (POEs) containing lactic acid dimers in the polymer backbone for possible use in controlled drug release applications is described. These autocatalyzed POEs are prepared by the acid catalyzed condensation of 3,9-diethylidene-2,4,8,10-tetraoxaspiro(5,5)undecane with diols to produce linear polymers. The diols used were a mixture of decanediol-lactate and decanediol in various molar ratio to produce polymers with different lactic acid contents. Polymer structures were confirmed by 13C NMR, 1H NMR, and FT-IR and physico-chemical properties, such as molecular weights, glass transition temperatures and viscoelastic behavior, were also determined.