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 applicati ons is described. These autocatalyzed POEs are prepared by the acid catalyz ed condensation of 3,9-diethylidene-2,4,8, 10-tetraoxaspiro(5,5)undecane wi th diols to produce linear polymers. The diols used were a mixture of decan ediol-lactate and decanediol in various molar ratio to produce polymers wit h different lactic acid contents. Polymer structures were confirmed by C-13 NMR, H-1 NMR, and FT-IR and physico-chemical properties, such as molecular weights, glass transition temperatures and viscoelastic behavior, were als o determined.