Fluorinated nanofibers for potential biomedical applications

Official URL: http://risc01.sabanciuniv.edu/record=b1221094 (Table of Contents)

The application of supercritical carbon dioxide has been attracting more attention in the synthesis of biodegradable polymers. Highly pure products without residues can be recovered after the polymerization in supercritical carbon dioxide. In the present work, three types of block poly(L-lactide-co-s-caprolactone), with a central fluorinated segment and polylactide/polycaprolactone side chains were synthesized by sequential ring-opening polymerization in supercritical carbon dioxide. Perfluoro polyethers can be used as blood substitutes to deliver oxygen to tissues so that these materials are promising for biomedical applications. In the first part of the work, fluorinated reactive stabilizers (prepolymers) with inner fluorinated segment and polylactide or polycaprolactone side chains were synthesized in bulk from three different fluorinated alcohols. The prepolymers were then utilized for the synthesis of copolymers in supercritical carbon dioxide, where polylactide segments were successively incorporated to the ends of the prepolymer, forming a block structure with polyester side chains. Solubility tests of the prepolymer and the pentablock copolymer in supercritical carbon dioxide showed effective solubilization at the reaction temperature and pressure. In the second part of the work, with the process of electrospinning, nanofiber webs were prepared from these biodegradable materials. Material characterization was carried out by nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), optical microscopy and scanning electron microscopy (SEM).