Heterogeneous mesoporous SBA-15 silica as catalyst towards the synthesis of various biodegradable aliphatic polyesters

Biocompatible and biodegradable polyesters have immense potential in medical applications as drug delivery vehicles and tissue engineering scaffolds. In this study, we synthesized biodegradable aliphatic polyesters, namely poly(butylene pimelate) (PBPi), poly(butylene succinate) (PBSu), and poly(butylene sebacate) (PBSe), by the polycondensation of equimolar quantities of dicarboxylic acid and diol using mesoporous SBA-15 silica as heterogeneous catalyst. We then compared its performance with a conventional homogenous catalyst, SnCl2·2H2O, which did not form these polymers. The synthesized SBA-15 catalyst was characterized by electron microscopy, nitrogen adsorption-desorption isotherm and infrared spectroscopy. The synthesized polyesters were evaluated using infrared spectroscopy, X-ray diffraction, nuclear magnetic resonance spectroscopy, differential scanning calorimetry, gel permeation chromatography, scanning electron microscopy and goniometry. The combined results demonstrate that the SBA-15 mesoporous catalyst formed higher molecular weight degradable polyesters in addition to higher yield and purity, thus confirming the superiority of the mesoporous silica catalyst for polymer formation. [graphic not available: see fulltext]