Polyesters Inspired by Glycerides: Enzymatic Polycondensation, Structure, Properties, and Nanoparticle Preparation

The polycondensation of glycerol and aliphatic dicarboxylic acids catalyzed by Candida antarctica lipase B absorbed on a macroporous acrylic resin (CALB) results in polyesters composed of repetitive units structurally similar to mono-, di-, and triglycerides. Adipic, suberic, sebacic, and dodecanedioic acids were investigated for the CALB-catalyzed polycondensation with glycerol in solution and bulk. In both conditions, the CALB-catalyzed esterification of primary hydroxyl of glycerol and acyl migration occurs in parallel and results in branched polyesters. Higher molar mass polyesters were obtained in reactions performed in bulk and using longer diacids than in solution and using shorter diacids. These glyceride-like polyesters have different amphiphilicity and physical properties that change from more hydrophilic and amorphous for poly(glycerol adipate) to more hydrophobic and semicrystalline for poly(glycerol dodecanedioate). The amphiphilicity of these polyesters allowed the production of nanoparticles with a hydrodynamic radius in the range of 35–270 nm and a negative zeta potential.