Functional aliphatic polyesters based on cycloaddition methodologies.

摘要

Polyester degradation in vivo allows the construction of temporary biomedical devices for wound closure, implants, and cargo delivery. The commercially available polyesters for these purposes lack polar or reactive functional groups, inherently limiting the versatility and effectiveness of these technologies. Many attempts have been made to incorporate functional groups into polyesters, mostly based on ring-opening polymerization methodologies. In this work, step-growth polymerizations are combined with cycloaddition reactions to include functional groups in new monomers and polymers that could be useful materials in biomedical engineering. First, the Diels-Alder cycloaddition was employed to synthesize a new family of dicarboxylic acid and anhydride monomers from various dienes. Amorphous, hydrophobic polyesters were attained in high molecular weight, including polymers containing polar functionality (amines and ethers). Thermosetting reactions yielded elastomers with mechanical properties similar to soft tissue that degraded in a slow, linear manner. A second methodology was developed based on the copper(I)-catalyzed azide-alkyne cycloaddition, in which an azide-containing diester monomer was synthesized and incorporated into aliphatic polyesters. These materials were then reacted with amine-containing alkynes to yield polyesters grafted in high density. All materials were fully characterized to better understand the structure-property relationships.